How Hard is the ISA Certified Arborist Exam?
One of the most common questions prospective arborists ask is: Is the ISA Certified Arborist exam hard? The short answer is yes, it is a challenging exam that requires significant preparation, even for experienced professionals. However, with the right study strategy, passing is very achievable.
ISA Certified Arborist Exam Pass Rate
While the International Society of Arboriculture (ISA) does not officially publish exact pass rates every year, historical data and industry consensus suggest the first-time pass rate for the ISA Certified Arborist exam is roughly 60% to 70%.
This means that around 1 in 3 test-takers do not pass on their first attempt. The exam is rigorous by design to ensure that only qualified individuals receive certification, protecting the integrity of the credential.
What is the Passing Score?
To become a Certified Arborist, you must achieve a passing score of 72%. The exam consists of 200 multiple-choice questions, which means you need to answer at least 144 questions correctly.
Because there is no penalty for guessing, you should make sure to answer every single question on the exam, even if you are unsure of the answer.
Why is the Exam Difficult?
The exam is considered difficult for a few key reasons:
- Breadth of Knowledge: The exam covers 10 distinct domains, ranging from Tree Biology and Soil Science to Risk Assessment and Pruning. Many arborists excel in practical skills like pruning or removal but may have less experience with the academic sides of Soil Science or Tree Biology.
- Tricky Question Phrasing: Questions are often designed to test your deep understanding rather than simple memorization. You may be presented with multiple answers that seem plausible, requiring you to identify the best practice according to ISA standards.
- Time Management: You have 4 hours (240 minutes) to answer 200 questions. That gives you roughly 1.2 minutes per question. Maintaining focus and pacing for four hours is a mental endurance test.
How to Ensure You Pass
Don't let the pass rate discourage you. The candidates who fail are often those who underestimated the exam and relied solely on their field experience rather than studying the ISA material. To ensure you pass:
- Don't Rely Only on Field Experience: Field experience sometimes diverge from textbook best practices. The exam tests your knowledge of ANSI standards and ISA Best Management Practices (BMPs), not necessarily how your specific crew operates.
- Identify Your Weaknesses Early: Take a baseline practice exam to see which of the 10 domains you struggle with most. Focus your study time there.
- Use Practice Questions: Reading the study guide is not enough. You must test your active recall. Our ISA Flashcards app provides hundreds of domain-specific flashcards and realistic mock exams to simulate the real testing environment and ensure you are ready for exam day.