Background: Dermatologic problems restrict the normal use of a prosthetic limb. The importance of contact dermatitis to skin morbidity in a population of amputees and the selection criteria for patch testing have not been clearly defined. Objective: We describe the range of dermatoses seen in a population of amputees and examine the incidence, causes, and patterns of contact dermatitis. Methods: This is a questionnaire-based, cross-sectional study of 210 amputees. Those with a skin problem were assessed by a dermatologist. Patch testing was undertaken in patients with persistent dermatitis. Results: A total of 34% of amputees experienced a skin problem. Lesions resulting from friction, pressure, and occlusion are common. Allergic contact dermatitis is seen in a third of patients with stump dermatitis. There are no features that distinguish allergic from irritant (chemical or physical) dermatitis. Conclusion: Dermatologic problems are common in prosthetic limb users. Allergic contact dermatitis is a significant problem, and all patients with dermatitis on the residual limb should be patch tested. (J Am Acad Dermatol 2000;42:501-7.)