This evaluation investigates the quality of digital skin images submitted by patients, and evaluates the feasibility of making a diagnosis and suggesting therapeutic intervention without direct physical examination. A broad sample of patients who called the Swiss Centre for Telemedicine for a skin problem, were invited to receive an oral and an electronic tutorial and to submit digital images of the lesion. All patients (N = 46) who submitted digital images of their skin problems during a two week period were included in the evaluation. Images were electronically transferred to a dermatologist from an independent office. Seventy-four percent of image sets contained focused images, and 72% contained adequate detail. Making a specific diagnosis was feasible in 67% of cases, and the dermatologist was able to narrow down the differential diagnosis in an additional 17%. Recommending therapeutic interventions was possible for the skin problems of 70% of patients. In conclusion, most digital skin images submitted by patients are of sufficient quality, and establishing a dermatological diagnosis is feasible in most cases. These results contribute to the validation of teledermatological processes based on patient-supplied skin images.