Background. Physical education (PE) is a key setting for children to engage in health-enhancing physical activity (PA). Factors influencing PE enjoyment in secondary schools are well researched. Less is known, however, about the factors children in elementary schools perceive to be important in promoting enjoyment, and how the current PE delivery framework in UK primary schools (combining specialist external coaches and generalist teachers) impacts on children?s motivational experiences. According to self-determination theory (SDT), enjoyment of activities is an intrinsic motivator for sustained engagement. Understanding children?s perceptions of PE is therefore critical if PE instructors are to increase enjoyment and the promotion of PA within and beyond PE. Purpose. To investigate children?s perceptions of factors that influence PE enjoyment, and interpret findings in the context of SDT and the promotion of autonomous motivation. Participants. Primary school pupils recruited from a cluster of four schools within a socio-economically deprived area of a large city in the North-West of England. Data collection and analysis. Eight focus groups were conducted with 47 children (23 boys) aged 7-11. Mixed gender focus groups included 4-6 children clustered by school years 3-4 (ages 7-9 years) and 5-6 (ages 9-11 years). Children were asked about their PE experiences and factors that influenced their perceived PE enjoyment. Transcripts were transcribed verbatim and analysed thematically using NVivo10 analysis software. Findings. Factors reported to influence children?s perceived PE enjoyment included 1) individual preferences, 2) peer behaviour, 3) instructor behaviour. Findings were interpreted in relation to SDT, and recommendations are given to help instructors and schools create a PE environment that enhances children?s enjoyment of PE. Conclusions. PE instructors and peers are important in creating an environment that supports children?s psychological needs for autonomy, competence and relatedness, which influence PE enjoyment. To consistently provide children with enjoyable PE lessons, primary schools are advised to support the ongoing development of generalist teachers and facilitate better working relationships between generalist teachers and specialist coaches. SDT can be used by instructors to guide practice that enhances children?s enjoyment of PE.