Occupational therapy candidates face a challenging task on the path to becoming registered occupational therapists. Uncertainty surrounds the professional community as to why certain candidates, who otherwise perform soundly both academically and clinically, struggle to be successful on the certification exam. Literature suggests that factors such as stress and anxiety may be the root cause. There is a plethora of literature discussing the importance of clinical reasoning skills in occupational therapy practitioners and students. However, no literary sources to date have investigated the importance of clinical reasoning in certification exam performance. This research study investigated the correlation between clinical reasoning skills and performance on the NBCOT certification examination. Thirty-five candidates from across the U.S. completed the Health Sciences Reasoning Test (HSRT), which tests critical thinking skills in five key areas. Supporting demographic information was collected for further comparisons. The participants then sat for the NBCOT exam within 90 days of taking the HSRT. Pearson product-moment correlation and Spearman's rho analyses indicated significant relationships between certification exam performance and three sub-skills of reasoning: inductive reasoning (p = .032/r_s = .011), deductive reasoning (p = .007/r_s = .004), and analytical reasoning (p = .001/r_s = .002). Total HSRT score was also a significant factor in exam performance (p = .001/r_s = .003). In ANOVA analysis investigating the relationship between highest educational level and certification exam performance, students who earned only master's degrees in occupational therapy performed significantly better than those earning combined bachelor's/master's degrees (p = .000), scoring an average of 29.15 points higher on the certification exam. In additional analysis, multiple regression analysis indicated that only analytical reasoning was a predictor of certification exam score. Race, age, grade point average (GPA), geographic location, and fieldwork settings were not significant factors in certification exam performance. Application of these results to larger populations should be exercised with caution due to the limited sample size of this study. Results of this study can initiate a dialogue among occupational therapy practitioners and educators who hold a role in assisting students in developing clinical reasoning skills and preparation for the certification exam. Results are also beneficial for students who can incorporate clinical reasoning skills as part of a certification exam study regimen.