Health care professionals (medical students, practicing physician's assistants, and residents in the specialties of internal medicine, surgery, and dermatology) were evaluated for their ability to diagnose malignant and benign skin disease. It was found that dermatology residents did significantly better in the diagnosis of malignant and benign skin disease than all other groups, and there was no significant difference among medical students, physician's assistants, and residents in internal medicine or surgery. Findings suggest that the current ability of nondermatologists to correctly diagnose malignant and benign skin disease is not at a comparable level to that of dermatologists and that a 1-month training period in the specialty of clinical dermatology during the primary care residency training period may be inadequate for training nondermatologists to distinguish malignant from benign skin disease. In some specialty areas, such as dermatology, specialization may be preferable to a primary care approach for initially evaluating skin disease.