ABSTRACT Introduction It is widely accepted that definitive surgical treatment for primary cutaneous melanoma should occur promptly, but the effects of a delay between initial diagnosis and definitive surgery remain unclear. In addition, high quality evidence is lacking for an optimal time‐to‐surgery from initial melanoma diagnosis. The aim of this study was to determine whether the timing of surgical treatment for Stage I & II melanoma was associated with survival outcome and whether there was an optimal time interval between melanoma diagnosis and definitive surgical treatment with respect to survival. Methods This was a retrospective cohort study of patients with primary cutaneous melanoma treated at a single institution between 1990 and 2015. The associations between time‐to‐surgery and clinical outcomes including overall survival (OS) and recurrence‐free survival (RFS) were described using the Kaplan–Meier method. Multivariable Cox proportional hazard models were used to quantify the relationship between each time‐to‐surgery cohort and clinical outcome. Results In total 18, 242 patients were included in the analysis. Their average age was 57.5 years and 57% were male. The majority of primary melanomas were located on the trunk (32.5%) and upper limb (24.7%). Mean Breslow thickness was 1.8 mm (range 0.1–50 mm) and 64% were of superficial spreading subtype. Time to surgery was divided into ≤ 1 week, 1–4 weeks, 4–8 weeks, 8–12 weeks and > 12 weeks ( n = 2453, 8882, 5906, 870 and 126, respectively). Increased delay of definitive surgical treatment was associated with poorer OS and RFS, with an OS HR of 1.23 for the 8–12 week group compared to the 1–4 week group. For RFS HR was 1.36 for the same cohorts. Conclusion Definitive surgical treatment of patients with primary cutaneous melanoma between 1–4 weeks post‐diagnosis with excision‐biopsy was associated with improved OS & RFS compared to those treated within 1 week and greater than 4 weeks in this patient cohort treated prior to the use of adjuvant drug therapy.