Objective: The purpose of the present study was to assess children's physical activity, social play behaviour, activity type and social interactions during elementary school recess using a pre-validated systematic observation system. Design: Cross-sectional. Setting: Two elementary schools located in Merseyside, England. Method: Fifty-six elementary school children (27 boys, 29 girls) were systematically observed during recess over a three-month period using a standardized physical activity observation instrument. Results: The results revealed the boys were engaged in significantly higher levels of physical activity during recess than girls. The boys were also involved in more sport-specific activities and participated in larger group sizes. Positive associations between physical activity and availability of equipment during recess were also reported. Conclusion: This study has confirmed recess as a valuable opportunity for elementary school children to increase their levels of physical activity. However, further studies with larger sample sizes need to identify and explore the relationship between physical activity (PA) and availability of equipment. (Contains 4 tables and 1 figure.)