BACKGROUND: Erythroplasia of Queyrat (EQ) is an intra-epithelial carcinoma of the penis. Progression to invasive carcinoma may occur. Its cause is unknown but some evidence suggests infection with human papillomavirus in the pathogenesis of EQ; however, recent data do not confirm this. Therapy is difficult and associated with important recurrence rates. Photodynamic therapy (PDT) employs a photosensitizer excited by visible light. The resulting photodynamic reaction selectively destroys atypical cells. Only few reports exist on the use of topical PDT in the treatment of EQ. OBJECTIVE: We report 11 cases of EQ treated by topical methylaminolaevulinic acid (MAL) PDT. RESULTS: Out of 11 male patients with EQ treated by topical MAL-PDT, 3 achieved complete remission sustained for 24 and 51 months and 4 a partial remission sustained for 2-45 months with a follow-up period of 4-45 months (1 patient lost to follow-up); surprisingly, 2 of the 4 patients with partial remission presented a complete remission after 20 and 45 months of follow-up, respectively, without further therapy. Four patients showed progression of the disease. CONCLUSION: Whereas topical MAL-PDT offers the advantages of tumour specificity, preservation of function and a good cosmetic result, side effects may cause treatment discontinuation in some cases. Treatment of EQ with PDT may represent a valuable option in selected cases, but our data do not allow considering it as a first-line therapeutic option.