Certified Arborist Exam

The International Society of Arboriculture’s (ISA) Certified Arborist examination is a voluntary certification that certifies an individual’s attainment of advanced knowledge and skill in arboriculture.


Candidates must have three years of experience in arboriculture or a combination of experience and education. Letter(s) of reference may be submitted as proof of work experience, and volunteer work may be used for the experience if the work is supervised and documented.

Test Design

A certified arborist has taken additional steps to understand the why and how of the tree cycle. From growth to the end of life, an arborist understands the influences and can develop and implement a life-cycle plan that ensures the proper growth of each species. This knowledge includes proper selection, establishment, and biology of the trees in their care.

There are 200 multiple-choice questions, and you will have three and a half hours to complete the exam. The time-limit and number of questions are the same regardless of the test delivery method. There are ten content knowledge categories:

  • Soil management – 12% of the exam
  • Identification and selection – 8% of the exam
  • Installation and establishment – 5% of the exam
  • Safe work practices – 15% of the exam
  • Tree biology – 8% of the exam
  • Pruning – 16% of the exam
  • Diagnosis and treatment – 12% of the exam
  • Urban forestry – 7% of the exam
  • Tree protection – 4% of the exam
  • Tree risk management – 13% of the exam

The exam is intended to test your knowledge over a broad range of competencies that a general arborist will encounter during their career. Certification does not confer legal status to practice, and continuing education is required throughout your time as an arborist to maintain certification.

Test delivery method

There are two options available for test delivery. The first option is a traditional pencil and paper examination. The paper-based method is only offered at a chapter or affiliated organization of the International Society of Arboriculture (ISA). This method has a predetermined test delivery schedule and results of the exam may take up to six weeks to receive.

The second method is computer-delivered. Computer-based exams are administered at a testing facility with the opportunity to schedule the exam at a time, location, and date that is convenient to the test taker. While there is an additional $125.00 fee to take the computer-based exam, results are immediate.

Both the paper-based and computer-based exams are equal in their difficulty level. Which method you chose is solely up to you. Are you better with a pencil in your hand? Then schedule the paper-based exam. Is it important to you to have immediate results? Then the computer-based method is better.

Registration and cost

Registration is $170.00 for International Society of Arboriculture (ISA) members and $280.00 for non-members for the paper certification exam of ISA Certified Arborist. If you choose to take the computer-based exam, there is an additional fee of $125.00 required. Computer-based exams are scored immediately, and the results are provided after you complete the exam.

Test Day

Verify your testing location and time before you leave for the exam. Allow yourself enough time to find parking, secure your valuables, and complete any necessary paperwork before your examination appointment. Personal belongings and study aids are not allowed in the testing center. All supplies needed for the exam will be provided to you.

Exam scoring and results

To obtain certification, you must receive a 76% or higher on the examination. Each domain is weighted, and the average is not equal to your overall score. Regardless of the test method, all candidates receive a detailed report of their test. The complete report will discuss your strengths and weaknesses, so you will know where to enhance your study for the future.

You may retake the exam as many times as required and the first retake is free. Each test after the first free retake cost $75.00 each, within one year of taking the exam the first time. If you have not passed the certification exam within that year, the exam test fee is $170.00 for ISA members or $280.00 for non-members.

How Can I Prepare for the Certified Arborist Test?

That’s a great question.  We’ve broken down the answer into three parts.

  1. Do yourself a favor and study.  Do not walk in unprepared. We have recommended prep materials below, but that only helps if you actually try.  Plus, studying is actually proven to be the best antidote to test anxiety.
  2. Take care of yourself.  Make sure you’re eating well, exercising, and sleeping.  All of these things are scientifically linked to brain performance.  If you take care of your body, you’ll be helping your grades.
  3. Get a study guide or set of flashcards.  Some people study better a certain way. Find your study strengths and make the most of them.  We’ve tried to make it easy for you by tracking down the best study guide and flashcard set for your exam.  Below you’ll see links to both!

Study Guide



Last Updated: April 27, 2020