Background: Dermatologists have greater accuracy than nondermatologists for diagnosis of skin disease. However, it is not clear whether this affects medical outcome. Objective: We tested the hypothesis that nondermatologists would be more Likely than dermatologists to prescribe combination products for the treatment of common fungal skin infections. Methods: We analyzed office-based physician visits for fungal skin infections recorded in the 1990-1994 National Ambulatory Medical Care Survey. Results: There were 4.1 million visits for cutaneous fungal disease of which 82% were to nondermatologists. Nondermatologists were more likely to prescribe combination agents (34.1%) than dermatologists (4.8%, p = 0.001). if the percentage of combination agents used by nondermatologists was reduced to that of dermatologists, an estimated $24.9 million or $10.3 million would be saved if clotrimazole or ketoconazole, respectively, were the substituted-drug for the combination agent clotrimazole/betamethasone dipropionate. Conclusion: Nondermatologists are more likely to use a more expensive, less effective regimen than are dermatologists, suggesting that dermatologists are more cost-effective than nondermatologists in the treatment of common fungal skin disorders.