BACKGROUND: Young people are often used as interpreters for family members in the primary healthcare setting. AIM: To explore bilingual young people's accounts of interpreting for family or friends in primary care settings. DESIGN OF STUDY: Qualitative study using in-depth interviews. SETTING: Community and youth groups in London. METHODS: Young people aged nine to 18 years old (n = 77) were purposively sampled to include those from established and recently arrived groups and were from Vietnamese, Kurdish, Bangladeshi or Eastern European backgrounds. Participants were interviewed one-to-one or with a friend, and interview transcripts were analysed to identify key themes. RESULTS: Young people were used for interpreting because of deficiencies in services, and also by choice. They identified advantages and disadvantages in their experiences. The majority of healthcare encounters were regarded as unproblematic. Three factors contributed to less successful encounters: healthcare professionals' or patients' communication skills; young people's own language skills, and the nature of the healthcare problem. CONCLUSION: This study identifies ways in which primary care professionals could facilitate better communication in encounters where young people are used as interpreters.