Many girls in the UK do not achieve recommended daily physical activity (PA) levels. Primary schools are required to provide 30 minutes of PA a day for pupils, with breaktimes providing an opportunity for children to be physically active. This study explored girls breaktime experiences to uncover participation barriers faced, with recommendations for schools to address these made, to improve the likelihood of children reaching recommended daily PA levels. Data was collected from three schools using focus groups consisting of 4/5 girls aged 9-11 years (Key Stage 2). A mind-map activity was also utilised. A thematic analysis was carried out, using transcripts and maps, to identify the barriers which made PA less appealing and more difficult for girls. The most common themes contributing to girls being less physically active than boys were: male domination of space and equipment, a lack of adult input, and little variety of play. Boys engaged in more PA due to dominating equipment sharing, creating an environment where girls felt unsafe and became tired due to a resultant lack of game variety. Based on these findings, breaktime PA should be promoted through: additional equipment provision, increased skilled adult involvement, and the creation of alternative PA options away from the male-dominated environment.