 Skin cancer is one of the most common human cancers with a rising incidence and considerable negative impact on human health. Exposure to ultraviolet radiation UVR in sunlight is the major aetiological factor in skin cancer initiation and progression. Human case-control studies have reported an inverse relationship between dietary fish or omega-3 polyunsaturated fatty acid PUFA intake and occurrence of non-melanoma skin cancer. Omega-3 PUFA have the potential to reduce the risk of photocarcinogenesis primarily by their ability to reduce production of prostaglandin E2 and consequently photoimmunosuppression. To date, no studies have assessed the impact of omega-3 PUFA on skin photoimmunosuppression in humans. 