PURPOSE:To explore the experiences of physiotherapists delivering community-based progressive resistance training for people with Prader-Willi syndrome (PWS). METHOD:Participants in this qualitative study were fifteen physiotherapists (13 female) who had supervised 14 young adults with PWS to complete a progressive resistance training program, twice per week for 10 weeks. Semi-structured interviews with the physiotherapists were audio-recorded and transcribed verbatim. Interview transcripts were checked for accuracy by the physiotherapists. Data were analysed using thematic analysis with an inductive approach and data were managed using NVivo software. RESULTS:Development of positive rapport between physiotherapists and people with PWS emerged as the critical factor. Components of developing positive rapport with a person with PWS included clear communication, adaptability in approach, fostering independence in the person with PWS, and motivating the person by developing confidence. Creating a routine, empowering the people with PWS to take ownership of their progress and developing confidence made continued participation in exercise by the people with PWS more likely. CONCLUSIONS:Our findings highlight the importance of developing rapport with people with PWS to facilitate their participation in exercise. Physiotherapist attributes and skills such as adaptability and communication positively influence participation in community-based exercise for people with PWS. Implications for rehabilitation The critical factor for maximising the participation of people with PWS in high-intensity exercise is the development of positive rapport by the physiotherapist Development of positive rapport was facilitated by therapist adaptability and clear communication. People with PWS might be motivated to exercise by developing their confidence and fostering their independence.