Fourteen variables were tested for their prognostic usefulness in 203 patients with clinical Stage I melanoma and primary tumor 0.76-169 mm thick. Only two variables, primary tumor location and level of invasion, were useful in predicting death from melanoma for these patients. Of the 12 deaths from melanoma, 11 occurred in patients with primary tumors located on the upper back, posterior arm, posterior neck, and posterior scalp (=BANS). There has been only one death from melanoma in 136 patients with melanoma located at other sites (11/67 vs 1/136, p less than 0.0001 Fisher's Exact Test). Of the 67 BANS patients, 51 had level II or level III lesions and five (10%0 died of melanoma. This compared with six deaths from melanoma in 16 patients (37.5%) with level IV BANS lesions (5/51 vs 6/16, p = 0.01 Fisher's Exact Test). The relatively high incidence of both melanoma deaths and regional node metastases for the BANS group merits consideration for testing the efficacy of elective regional node dissection for these patients.