The keratinocyte skin cancers, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), together constitute around half of all cancers diagnosed in Australia: a greater burden on public health than anywhere else in the world. Excessive sun exposure is the predominant cause but differences in the causal pathways for each major type of skin cancer are still not understood. Relative intensity and dose of causal sun exposure vary and perhaps timing with respect to the life-course as well. By developing and integrating epidemiological and laboratory evidence collected over a 20-year period in a community-based skin cancer study, the Nambour Skin Cancer Study, this project aims to definitively clarify skin cancer aetiology and therefore prevention measures. In addition we aim to provide rarely available cost estimates of skin cancer in this community sample.