ObjectivesTo explore whether knowledge about the harms of ultraviolet radiation (UVR) influences UK university students' sun-related behaviours and examine in depth their attitudes towards: sun protection, natural and artificial tanning behaviours.DesignQualitative methodology with 15 semistructured, individual interviews. Thematic analysis using the Framework Method with analyst triangulation and member validation.SettingOne university in the West Midlands, UK.Participants15 Caucasian male (n=4) and female (n=11) students, aged 18–22 years, from a UK university. Participants were recruited using convenience sampling from the university's main campus followed by purposive sampling for: gender, course and sun-related behaviours.ResultsFive main themes emerged: (1) knowledge of UVR; (2) sun-protection practices; (3) attitudes towards tanning; (4) external influences and (5) internal influences. All students knew the associated skin cancer risks from the sun and sunbed use, but this did not appear an important influence in their sun-related behaviours. Body image strongly motivated sun-protection practices and the desire to tan naturally or artificially, across both genders. However, participants' final decision-making appeared to be influenced by their beliefs that practising known harmful sun-related behaviours would not affect them or the perceived susceptibility to sunburn. Beliefs about sunbathing and sunscreen use prompted improper use of sun protection and inadvertently caused more harmful practices. Participants' peers, family and the media had dual roles influencing the development of attitudes towards sun protection and tanning, which contributed to how participants behaved in the sun and their engagement in tanning methods.ConclusionsKnowledge about the risk of skin cancer associated with UVR did not strongly influence sun-related behaviours, whereas body image appeared as a key motivator. Attitudes towards sun protection and tanning stemmed from the media, peers and family, and particularly from childhood habits. Public health strategies may benefit from appearance-related skin cancer prevention campaigns, encouraging safer parental sun-related habits and correcting sun-related misconceptions.