Background Even though both the involvement of regional lymph nodes and the number of metastatic lymph nodes are regarded as major determinants of survival in cutaneous melanoma, the extent of node dissection has been analyzed as an independent prognostic indicator in only a few studies. This study aims to determine how the extent of lymph node excision (EN) might predict the disease relapse and survival in melanoma. Methods A total of 317 patients with stage III melanoma were included in the study and reviewed retrospectively. The patients were divided into 2 groups based on the number of the excised lymph nodes: EN1 for fewer than 10 and EN2 for 10 or more lymph nodes removed. Results The median number of positive nodes was 1 (range, 1-32). The largest group was N1 (52.4%), which was followed by N2 (29.6%) and N3 (18%). The median number of EN was 13 (range, 1-73). The patients were allocated to EN1 and EN2 as follows: 31.9% and 68.1%, respectively. The rates of EN2 patients were 62.2%, 72.2%, and 78.2% in N1, N2, and N3, respectively. For all patients, the estimated 5- and 10-year relapse-free survival rates were 41% and 39%, respectively; and the estimated 5- and 10-year overall survival rates were 51% and 42%, respectively. Extension of lymph node excision was found to be not prognostic for relapse and survival (P = 0.55 and P = 0.88, respectively). Conclusions Extension of lymph node excision has no impact on relapse and survival of stage III cutaneous melanomas.