Background: Publications reporting photodynamic therapy (PDT) in mycosis fungoides (MF) are rare, involve small samples, and are difficult to compare because of a lack of technical standardization. Objective: We sought to assess PDT effectiveness and tolerability in early-stage MF using a strict reproducible procedure. Methods: This was a prospective study conducted in Nantes University Hospital, France, including patients older than 18 years with histologically proven MF (stage IA or IB). Methyl-aminolevulinic acid-PDT sessions were repeated monthly for 6 months. Clinical and histologic responses were assessed 1 month after the last session. Patient satisfaction was assessed by telephone survey. Results: Twelve patients (with 29 lesions) were treated with PDT. An objective response in target lesions was obtained in 75% of patients. Response rates were similar between plaques and patches but higher in sun-protected compared with sun-exposed areas (trend without reaching significance). During PDT, new lesions appeared in 5 of 12 patients in untreated areas. Most patients were highly satisfied and preferred PDT to the topical chemotherapy previously used. Limitations: PDT procedure criteria selection was partially arbitrary. Conclusions: In early-stage MF, PDT is effective and appreciated (especially when compared with conventional topical chemotherapy). Unilesional and paucilesional forms and lesions in sun-protected areas are to be preferred.