Thirty men with biopsy-proven premalignant or malignant squamous cell lesions of the penis were treated. All had subclinical aceto-white lesions with histologic evidence for human papilloma virus infection. Nineteen patients had penile intraepithelial neoplasia (PIN I and II) and 11 had squamous cell carcinoma. Of these 11 patients, 6 had noninvasive penile intraepithelial neoplasia—carcinoma in situ (PIN III/Tis)—and 5 had invasive squamous cell carcinoma (4 stage T2 and 1 T3). All were treated with laser: CO2 was used for low-stage lesions, Nd:YAG was used alone or in combination with CO2 laser for more histologically advanced lesions, and KTP/532 was used in one patient with squamous cell carcinoma (Tis). Follow-up in 23 patients for up to 2 years showed that all but 1 (stage T3) remained free from penile malignancy. Appropriate laser therapy for all but deeply invasive (T3) tumors controls local disease, producing results that are clinically equal and cosmetically and functionally far superior to partial penectomy. © 1992 Wiley-Liss, Inc.