Background: Protection from sun exposure is key in the prevention of photodamage and skin cancer, and is particularly important in countries that experience high ultraviolet exposure. We compare the knowledge, attitude and behaviour towards sun exposure in Singapore between adults with and without photodamage. We also describe the clinical features of patients with photodamage in Singapore. Methods: 532 subjects were recruited from the dermatology specialist outpatient of a tertiary hospital in Singapore. Each subject was assessed clinically by a dermatologist for evidence of photodamage, and answered a questionnaire assessing his knowledge, attitude and behaviour towards sun exposure and protection. Results: Subjects with photodamage were older, and had lower education and employment rates compared to subjects without photodamage. There was no significant difference in knowledge on the harmful effects of sun exposure and on sun protection or in sun avoidance behaviour (other than use of protective sunglasses) between the two groups, though more patients with photodamage felt that they take adequate sun protection measures. Of note, only a low percentage of subjects in both groups (24.5% of subjects with photodamage and 23.1% of subjects without photodamage) practise regular use of sunscreen. Conclusion: There was no significant difference between the knowledge, attitudes and behaviours of subjects with and without photodamage, though demographic differences between the two groups exist. Regular sunscreen usage is low in Singapore, a country with high exposure to ultraviolet light, and measures to educate and modify the behaviour of the public need to be developed.