Child characteristics including age, gender, risk-taking behaviour and sensation seeking are thought to influence children's ability to appraise risks. The present study investigated children's risk perceptions and appraisals in the context of common outdoor physical play activities. Risk perceptions and appraisal of four- and five-year olds were assessed using a pictorial risk appraisal measure and through individual semi-structured interviews examining children's decision-making. Sensation seeking and risk-taking behaviour were assessed using self- and parent-report measures. Results revealed that the children were able to identify injury risk behaviours however differentiating the severity of the potential injury was less accurate. Furthermore, the children appeared to use these judgements in their play to inform their behaviour whilst using playground equipment. Whilst they actively sought out those activities that offered challenge and excitement, they were aware of their abilities and showed caution in engaging in activities that were beyond their current capabilities. The results have implications for the provision of calculated risk-taking in outdoor play and for adult responses to the risk-taking behaviour of children. (Contains 5 tables.)