Background. Wearing sunglasses may reduce the risk of cataract and of skin cancer in the periorbital area. Understanding predictors of sunglasses use may help identify groups with lower usage patterns. Methods. An annual observational field survey of teenagers and adults at leisure at outdoor venues around Melbourne, Australia was conducted between 11 am and 3 pm on mainly sunny, summer weekends ( n = 42,207). The serial cross-sectional survey assessed sun protection behaviors, including use of sunglasses from 1993 to 2002, and other variables hypothesized to predict sun-related behavior (sex, age, SES, activity level and setting, size of social group, and weather conditions). Predictors of use of sunglasses were assessed using multivariate logistic regression. Results. 36.2% of those observed wore sunglasses, and this increased only slightly over the years. Sunglasses use was most common among those observed on sunny days, in no or partial shade, in parks/gardens and at pools/beaches, less active people and people on their own or in pairs, people observed in higher socio-economic areas, females, people 20–50 years of age, and people wearing head and clothes cover. Conclusion. Sunglasses use should be encouraged among the population in general and especially among golfers, tennis players, teenagers, males, and people in lower SES areas.