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200+ Free Certified Arborist Practice Questions

Pass your ISA Certified Arborist Exam exam on the first try — instant access, no signup required.

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50-60% Pass Rate
200+ Questions
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Questions by Category

Arborist-Diagnosis-Treatment28 questions
Arborist-Tree-Biology27 questions
Arborist-Soil-Water24 questions
Arborist-Pruning24 questions
Arborist-Risk-Assessment21 questions
Arborist-Tree-Identification20 questions
Arborist-Tree-Removal20 questions
Arborist-Nutrition-Fertilization16 questions
Arborist-Law-Ethics12 questions
Arborist-Tree-Support-Lightning8 questions
2026 Statistics

Key Facts: Certified Arborist Exam

72%

Passing Score

144/200 questions

50-60%

Pass Rate

First-time

200

Questions

Multiple choice

4 hrs

Time Limit

Approximate

3 years

Credential Valid

CEUs required

10

Content Domains

ISA Blueprint

The ISA Certified Arborist exam has a 50-60% first-time pass rate. The exam requires 72% (144/200 correct answers) to pass and covers 10 content domains based on the ISA Arborist Certification Study Guide. Candidates need 3+ years of full-time arboriculture experience or a related degree with 2 years experience. The credential is recognized worldwide and demonstrates professional knowledge in tree care.

About the Certified Arborist Exam

The ISA Certified Arborist exam is an internationally recognized credential for professional arborists. The exam covers 10 content domains: Tree Biology (16%), Tree Identification and Selection (10%), Soil and Water Relations (12%), Nutrition and Fertilization (8%), Tree Support and Lightning Protection (4%), Diagnosis and Treatment (14%), Pruning (12%), Tree Removal (10%), Risk Assessment (8%), and Arboriculture and the Law (6%).

Questions

200 scored questions

Time Limit

3.5 - 4 hours

Passing Score

72% (144/200)

Exam Fee

$295 (ISA members) / $460 (non-members) (International Society of Arboriculture (ISA))

Certified Arborist Exam Content Outline

16%

Tree Biology

Cell structure and function, woody anatomy, photosynthesis, respiration, transpiration, growth patterns, meristems, root systems, tree defense mechanisms, CODIT model

10%

Tree Identification and Selection

Native and ornamental species, conifers vs deciduous, species selection criteria, invasive species, dichotomous keys, hardiness zones

12%

Soil and Water Relations

Soil composition, texture and structure, pH and nutrient availability, drainage and aeration, water uptake, drought stress, irrigation systems

8%

Nutrition and Fertilization

Macronutrients (N-P-K), micronutrients, fertilizer types, application methods, soil testing, foliar analysis, deficiency symptoms

4%

Tree Support and Lightning Protection

Cabling systems, bracing rods, lightning protection installation, support hardware, guying and staking, inspection schedules

14%

Diagnosis and Treatment

Insect pest identification, disease diagnosis, abiotic disorders, IPM strategies, pesticide application, biological control, diagnostic techniques

12%

Pruning

Pruning objectives and techniques, crown cleaning/thinning/raising/reduction, proper pruning cuts, wound response, ANSI A300 standards

10%

Tree Removal

Hazard tree assessment, felling techniques, rigging systems, crane operations, chainsaw safety, work zone safety protocols

8%

Risk Assessment

Tree structure evaluation, decay detection methods, risk rating systems, mitigation strategies, Resistograph, tomography, load testing

6%

Arboriculture and the Law

Tree ownership, boundary law, liability and negligence, permit requirements, professional standards, ISA Code of Ethics, contracts

How to Pass the Certified Arborist Exam

What You Need to Know

  • Passing score: 72% (144/200)
  • Exam length: 200 questions
  • Time limit: 3.5 - 4 hours
  • Exam fee: $295 (ISA members) / $460 (non-members)

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

Certified Arborist Study Tips from Top Performers

1Focus on Tree Biology (16%) and Diagnosis/Treatment (14%) - these are the largest domains
2Understand the CODIT model (Compartmentalization Of Decay In Trees) - it is heavily tested
3Study ANSI A300 Pruning Standards and ANSI Z133 Safety Standards thoroughly
4Learn to identify common tree species in your region and understand their characteristics
5Master soil science concepts including texture, structure, pH, and nutrient availability
6Understand IPM (Integrated Pest Management) principles and strategies
7Study risk assessment concepts including the ISA Risk Assessment Matrix
8Review tree law concepts including boundary trees, negligence, and liability
9Practice with timed exams - 200 questions in 4 hours requires pacing of about 1 minute per question

Frequently Asked Questions

How hard is the ISA Certified Arborist exam?

The ISA Certified Arborist exam has a 50-60% first-time pass rate. It is considered moderately challenging due to the breadth of knowledge required across 10 domains. Success requires both theoretical knowledge and practical experience in arboriculture. Most candidates with 3+ years of experience who study for 60-80 hours pass on their first attempt.

What is the passing score for the Certified Arborist exam?

You need 72% (144 correct answers out of 200 questions) to pass the ISA Certified Arborist exam. The exam consists entirely of multiple-choice questions with no penalty for incorrect answers. Results are typically available immediately upon completion at testing centers.

What experience do I need to take the Certified Arborist exam?

ISA requires 3+ years of full-time arboriculture experience, or a 2-year degree in arboriculture/forestry/horticulture with 2 years experience, or a 4-year degree with 1 year experience. Experience must include direct work with tree care, pruning, diagnosis, or related activities. Documentation of work history is required when applying.

How long is the Certified Arborist credential valid?

ISA Certified Arborist certification is valid for 3 years. To maintain certification, you must earn 30 Continuing Education Units (CEUs) during each 3-year period or retake the exam. CEUs can be earned through ISA chapter events, workshops, conferences, college courses, and other approved educational activities.

What is the salary range for a Certified Arborist?

According to industry data and ISA surveys, entry-level arborists typically earn $35,000-$45,000 annually. Certified Arborists with 3-5 years experience earn $50,000-$70,000. Senior arborists, consultants, and those in management positions can earn $75,000-$100,000+. Certification typically increases earning potential by 10-20% compared to non-certified professionals.

How is the exam administered?

The ISA Certified Arborist exam is administered at PSI testing centers across the United States and internationally. The exam is computer-based with 200 multiple-choice questions and a time limit of 3.5 to 4 hours. Some regions also offer paper-based testing at ISA chapter events. You must apply and pay ISA directly before scheduling with PSI.

What study materials should I use?

The primary study resource is the ISA Arborist Certification Study Guide (available from ISA). Additional recommended resources include the ANSI Z133 Safety Standards, ANSI A300 Pruning Standards, and industry publications. Our practice questions here cover all 10 exam domains and include detailed explanations to reinforce learning.