AIM To investigate ownership and perceived utility of written asthma action plans (WAAPs) in general practice. METHODS: Questionnaires were completed by 225 adults and 75 children with GP-diagnosed asthma from 31 practices. Regression models for WAAP ownership allowed for confounders and clustering by practice. Five audio-recorded focus groups were conducted before questionnaire implementation and, 12 months later, six focus groups and additional in-depth interviews with 29 patients and 16 doctors were conducted. Transcripts were submitted to content and thematic analyses.