BACKGROUND AND OBJECTIVES: In Australia, the uptake of the sentinel lymph node biopsy (SLNB) appears low despite clinical practice guideline recommendations. The aim of this study was to describe the knowledge and attitudes of general practitioners (GPs) to SLNB. METHOD: GPs were recruited at an annual conference and a skin cancer skills workshop, and using GP professional communications. A mixed methods approach comprised a cross-sectional questionnaire and, for a subset of participants, semi-structured interviews. RESULTS: Overall, 231 GPs completed the questionnaire, of whom 23 were interviewed. One-third (32%) described themselves as quite or very familiar with the guidelines, and two-thirds (68%) thought that SLNB had an important role in the management of patients with melanoma. Of GPs who would discuss SLNB with eligible patients, <40% correctly identified that SLNB is recommended for patients with an invasive melanoma >1 mm thick. DISCUSSION: GPs were generally supportive of SLNB. Familiarity with the guidelines was low, particularly regarding which patients should be considered for SLNB.