Nd:YAG laser coagulation is possible for superficial tumors of the penis. The value of photodynamic diagnosis (PDD) and autofluorescence imaging (AF) in detecting malignant lesions on the penis was evaluated. Twelve patients with biopsy-confirmed squamous cell cancer (SCC) of the penis were examined with PDD and AF. For the PDD and AF the penis was illuminated with the blue excitation light from a xenon arch lamp. Biopsies were taken from suspicious lesions detected by PDD or AF and then treated with Nd:YAG laser coagulation. Neoplastic lesions presented with a positive red fluorescence under PDD or a diminished appearance under AF. The HPV-analysis was positive in eight of the 12 lesions. Fluorescence diagnosis is used for the detection of neoplastic lesions. It assists the urologist in detecting neoplastic and preneoplastic lesions, ensuring a more reliable destruction of all tumor material in penile sparing surgery.