Background: The school playground can promote physical activity for large numbers of children. The aim of this study was to identify areas of the playground that children visited at break-times, the decisions according to gender and the influence of contextual and environmental variables on PA levels. Methods: The playground of a culturally diverse primary school was observed during morning break times and lunchtimes. Counts of sedentary, LPA, and MVPA episodes, and the contexts in which they occurred were recorded using the system for observing play and leisure in youth (SOPLAY). Results: Areas promoting ball sports had higher counts of boys (mean ± SD; 9.9 ± 4.8) compared to girls (2.0 ± 3.5) and areas promoting climbing and social interaction had higher counts of girls (7.9 ± 7.2) compared to boys (3.5 ± 2.9). The proportion of MVPA episodes during all break-time was 34% ± 26%. Areas of the playground with organised activities had 2.70 (95%CI: 1.87 to 3.91) times higher MVPA counts than areas ‘not organised’. Similarly, areas with ‘supervision’ were associated with higher MVPA counts (1.34; 1.18 to 1.53) compared ‘not supervised’ areas. Conclusion: Organisation and supervision might influence PA choices and PA levels of children in the primary school playground. Further investigation is required to explore different playgrounds settings, and context and gender preferences.