Sentinel lymph node biopsy (SLNB) provides accurate nodal staging in patients with melanoma. However, its prevalence across geographic regions is unknown. Our aim was to determine if SLNB for melanoma has been widely adopted throughout the United States. All patients in the Surveillance, Epidemiology and End Results (SEER) cancer registry for 2004 with melanoma were evaluated. Data were collected for demographics, depth of melanoma, and type of nodal evaluation (regional lymph node dissection vs SLNB). Registry sites were categorized into West, Midwest, Northeast, and Southeast. Chi2 analysis was performed to identify regional differences in receipt of SLNB. Overall, the West region (n = 2352) had a higher use of SLNB compared with the Midwest (n = 497), Northeast (n = 630), and Southeast (n = 268) regions (82.1% vs 77.9%, 65.4%, and 60.1%, respectively; P < 0.001). Intermediate-thickness (1 to 4 mm) melanomas had differences in SLNB use between the West and Midwest (83.6% and 81.4%) versus the Northeast and Southeast (66.3% and 60.2%) (P < 0.05). This population-based analysis shows low use of SLNB for melanoma in some U.S. regions. Further studies need to address the reasons for these differences and target ways to improve rates. Results suggest that SLNB may be considered as a potential quality measure.