Non-melanoma skin cancer (NMSC) is the most frequent malignancy in organ transplant recipients. The aetiology of NMSC after transplant is multifactorial. The aim of this study was to determine the clinical and environmental factors involved in the development of NMSC in a Spanish kidney transplant population from the Mediterranean region. A total of 289 patients who had received a kidney transplant during the period January 1996 to December 2010 were included in the study. Both prospective and retrospective data were used. All patients underwent a structured interview and a complete examination of the skin. After a median follow-up of 72 months (range 12-180 months), 73 of the 289 patients (25.2%) developed 162 tumours. The ratio of basal cell carcinoma to squamous cell carcinoma was 2.21:1. The cumulative incidence of NMSC increased with the duration of immunosuppression, from 20.78% at 5 years, to 37.35% at 10 years to 53.08% at 15 years after transplantation. Age at the time of transplant, phototype and occupational sun exposure were associated with a higher risk of NMSC. NMSC is a significant clinical problem in kidney transplant recipients. This has implications for the development of prevention and surveillance strategies. Clinical and environmental factors may be used to identify those patients who are at risk for NMSC.