Excess exposure to solar ultraviolet radiation (UVR) is the only readibly modifiable skin cancer risk factor. To assist with the design and evaluation of child sun protection interventions in schools and the community at large, this first comprehensive study used electronic monitors to record time- stamped, second-by-second UVR exposure of 325 New Zealand primary schoolchildren who kept a diary of their activities and sun-protective practices. They also completed a sun-related knowledge, attitudes and usual behaviours questionnaire. School principals and Health promoters were interviewed about school and community sun protection efforts. Passive activities were associated with the highest UVR exposure rates compared to active, travel and unclassified pursuits. Girls tended to have higher sun protection scores than boys, but were more likely to sunbathe and use sunscreen. When considering sun-related knowledge, attitudes and behaviours simultaneously, knowledge was only significantly associated with behaviours when mediated by attitudes. These findings will be developed into child sun protection messages.