Aims: To evaluate the role, if any, of sentinel lymph node mapping (SLNM) with biopsy (SLNB) in patients with thick cutaneous melanoma.Methods: Consecutive patients with thick (Breslow >= 4 mm) cutaneous melanoma, undergoing SLNB were identified from a departmental database comprising 550 patients in total from 2000 to 2010. Factors examined included demographic data, histological subtype, site and depth of lesion, percentage of positive SLNs, regional recurrence in the setting of a negative SLNB result (false-negative rate), complications, further lymphadenectomy, and follow-up (disease free and overall survival), where available.Results: Sixty-four eligible patients (37 men, 27 women) underwent primary excision and SLNM. Median patient age was 59 years (range 8-82 years). Mean Breslow depth was 7 mm (range 4-19 mm). Thirty melanomas were located on the limbs, 19 on the head and neck and 15 on the trunk. Twenty-three (35%) were ulcerated. Of the 57 patients who had a sentinel node identified, 18 (31%) had metastatic melanoma identified. The mean survival time for patients with a negative SLN was 79 months versus 18 months for those with a positive node. Patients with a negative SLN have a 5 year disease free survival of 79% versus 11% ( p < 0.001) and an overall 5 year survival rate of 85% versus 32% when compared to node positive patients.Conclusions: The status of the SLN is predictive of disease recurrence and overall survival in patients with a thick primary cutaneous melanoma. This modality should be employed, where applicable, in this cohort of patients. (C) 2011 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.