OBJECTIVE: To better understand the factors associated with the well-established gender difference in survival for patients with melanoma. SUMMARY BACKGROUND DATA: Gender is an important factor in patients with cutaneous melanoma. Male patients have a worse outcome when compared with females. The reasons for this difference are poorly understood. METHODS: This prospective multi-institutional study included patients aged 18 to 70 years with melanomas ≥1.0 mm Breslow thickness. Wide excision and sentinel lymph node (SLN) biopsy was performed in all patients. Clinicopathologic factors, including gender, were assessed and correlated with disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS). RESULTS: A total of 3324 patients were included in the covariate analyses; 1829 patients had follow-up data available and were included in the survival analyses. Median follow-up was 30 months. On univariate analysis, men (n = 1906) were more likely than women to be older than 60 years (P < 0.0001), have thicker melanomas (P < 0.0001), have primary tumor regression (P = 0.0054), ulceration (P < 0.0001), and axial primary tumor location (P < 0.0001). On multivariate analysis, age (P = 0.0002), thickness (P < 0.0001), ulceration (P = 0.015), and location (P < 0.0001) remained significant in the model. There was no difference in the rate of SLN metastasis between men and women (P = 0.37) on multivariate analysis. When factors affecting survival were considered, the prognosis was worse for men as validated by lower DFS (P = 0.0005), DDFS (P < 0.0001), and OS (P < 0.0001). CONCLUSIONS: Male gender is associated with a greater incidence of unfavorable primary tumor characteristics without an increased risk for nodal metastasis. Nonetheless, gender is an independent factor affecting survival. Copyright © 2006 by Lippincott Williams & Wilkins.