Statins may restrict cellular functions required for melanoma growth and metastasis. We examined whether long-term statin use commenced before diagnosis of the primary is associated with reduced risk of melanoma recurrence.We prospectively followed a cohort of patients newly diagnosed between 2010 and 2014 with localised tumour-stage T1b to T4b melanoma in Queensland, Australia. We used Cox-regression analyses to examine associations between long-term statin use and melanoma recurrence for the entire cohort, and then separately by sex and by presence of ulceration due to evidence of effect modification.Amongst 700 patients diagnosed with stage T1b to T4b primary melanoma (mean age 62, 59% male, 28% with ulcerated tumours), 94 patients (13%) developed melanoma recurrence within 2 years. Long-term statin users (n=204, 29%) had a significantly lower risk of disease recurrence compared to non-users (Adjusted hazard ratio (HRadj ) 0.55, 95% Confidence Interval (CI) 0.32-0.97) regardless of statin subtype or potency. Compared to non-statin users, risk of recurrence was significantly decreased in male statin-users (HRadj 0.39, 95% CI 0.19-0.79) but not female statin users (HRadj 0.82, 95% CI 0.29-2.27) and in statin-users with ulcerated (HRadj 0.17, 95% CI 0.05-0.52) but not non-ulcerated (HRadj 0.91, 95% CI 0.46-1.81) primary melanoma.Statins commenced before melanoma diagnosis, may reduce the risk of melanoma recurrence, especially in males and those with ulcerated tumours. Clinical trial evaluation of the potential role of statins in improving the prognosis of high-risk melanoma is warranted.