The authors evaluated construct validity of scores for the Comprehensive Osteopathic Medical Licensing Examination (COMLEX-USA), the examination used to evaluate osteopathic physicians for licensure. They computed correlations between students' grades in the first 2 years of osteopathic medical school and their scores on the COMPLEX-USA Level 1 (N = 187) and Level 2 (N = 86), as well as correlations between third- and fourth-year clerkship grades and the COMLEX-USA Level 2. Correlations of Level 1 scores with grades for years one, two, and the first 2 years combined were .74, .80, and .81, respectively; for Level 2, correlations were .59, .70, and .71. Correlation between clerkship grades and scores for the COMLEX-USA Level 2 was .26. The strong correlation between COMLEX-USA results and grades for the didactic curriculum in the first 2 years of medical school provides evidence for the construct validity of scores for the COMLEX-USA Levels 1 and 2.