PURPOSE: A worldwide web-based survey was conducted among melanoma surgeons to investigate opinions about completion lymph node dissection (CLND) in patients with positive sentinel nodes (SN). METHODS: A questionnaire was designed following input from a group of melanoma surgeons. Cognitive interviews and pilot testing were performed. Surgeons identified through a systematic-review of the SN and CLND literature were invited by email. RESULTS: Of 337 surgeons, 193 (57.2 %) from 25 countries responded (January-July 2011). Most respondents work in melanoma (30.1 %) and surgical oncology (44.6 %) units. In patients with a positive SN, 169 (91.8 %) recommend CLND; the strength of the recommendation is mostly influenced by patient comorbidities (64.7 %) and SN tumor burden (59.2 %). Seventy-one responders enroll patients in the second Multicenter Selective-Lymphadenectomy Trial (MSLT-2), and 64 of them (76 %) suggest entering the trial to majority of patients. In cases requiring neck CLND, level 1-5 dissection is recommended by 35 % of responders, whereas 62 % base the extent of dissection on primary site and lymphatic mapping patterns. Only inguinal dissection or ilioinguinal dissection is performed by 36 and 30 % of surgeons, respectively. The remaining 34 % select either procedure according to number of positive SNs, node of Cloquet status, and lymphatic drainage patterns. Most surgeons (81 %) perform full axillary dissections in positive SN cases. CONCLUSIONS: The majority of melanoma surgeons recommend CLND in SN-positive patients. Surgeons participating in the MSLT-2 suggest entering the trial to the majority of patients. More evidence is needed to standardize the extent of neck and groin CLND surgeries.