This research examines the school-based training experiences of a female trainee teacher of physical education (Emily) at a grammar school for boys. The purpose of this research is to consider whether the sex of the trainee teacher either inhibits or advances the professional development of trainee teachers in an opposite-sex school. Emily provided a continuous commentary through narrative accounts of her professional development within an all-boys grammar school whilst undertaking the final stage of her statutory school-based training in south-east England through the use of an on-line journal which generated computer-mediated data. Emily highlighted her initial anxieties; the challenges she faced during the placement; and her overall perceptions of training to teach physical education in a grammar school for boys. A post-placement interview also provided additional data with regards to her professional development. Further evidence of Emily's experiences and progress was provided by her mentor's final report and through e-mail correspondence. The findings suggest that whilst the sex of the trainee is a contextual factor to consider in an opposite-sex school it does not inhibit the professional development of the trainee and has little relevance to training to teach physical education in an opposite-sex school.