Sentinel lymphadenectomy (SLNE) is now internationally accepted for the primary treatment of melanomas thicker than 1 mm. But it is still controversial whether also patients with nonulcerated melanomas in the Breslow range between 0.76 and 1 mm should be included. At the authors' department, 87 of such patients (Group A) underwent SLNE in combination with wide local excision (WLE) of their primary melanomas in the years 1995 to 2001. SLN micrometastases were found in 10 of these patients (11.5%). Radical completion lymph node dissections (CLND) were added in 4 of the 10 patients without revealing any further nodal metastases. All the 87 Group A patients remained free from recurrent disease at a median follow-up time of 74 months. The control Group B from the same department encompassed 61 consecutive stage Ia patients with melanomas in the identical Breslow range, who had undergone only WLE of their primaries without SLNE in the years 1987 to 1993 (median follow-up time 115 months). Five of these 61 patients (8.2%) developed melanoma metastases within 12 to 68 (median 19) months of follow-up, 3 of them initially in regional lymph nodes. Four of the 5 individuals died because of the final distant dissemination of the melanoma. Kaplan–Meier comparisons between Groups A and B with log-rank testing showed a significantly worse outcome of Group B with respect to recurrence-free survival (p = 0.01), regional nodal progression (p = 0.041), distant metastasis (p = 0.023) and melanoma-related mortality (p = 0.03). The overall survival was not significantly different, because expiries not related to melanoma predominated in both groups. Our data suggest that SLNE seems to nearly completely eliminate the risk of melanoma recurrences in patients with melanomas between 0.76 and 1 mm thick. © 2007 Wiley-Liss, Inc.