Primary care physicians must identify and manage work-related disease, yet it is unclear whether training is adequate to accomplish this. This study examines the performance of 110 candidates, including 93 4th-year medical students, in the diagnosis and treatment of a standardized patient with occupational illness. Results indicated that the students did substantially better than the medical practitioners who had not received recent training. Although a strong correlation existed between candidates performance on the occupational health (OH) case and overall score on 19 non-occupational health cases, the competency measure that most determined performance on the OH case was interpersonal skills. A correlation also existed between working knowledge, data collection and data interpretation skills overall, and performance on the OH case; diagnostic skills, test selection, test interpretation, and case management skills overall showed no such correlation. The findings highlighted the importance of emphasizing interpersonal skills in training physicians to appropriately manage occupational medical cases, and illustrated the usefulness of standardized patients in teaching and evaluating occupational medical skills.