While the written part of the CNA exam isn't really that hard, the practical skills can be a little hard for Nursing Assistants. Generally, to pass the CNA test, you may need to get yourself a study guide, take as many CNA Practice Tests as possible, and practice as much as possible. This will help boost your knowledge and skill. The CNA exam can be hard to pass if you do not have the knowledge and skills needed to pass the exam.