Based on a three-year long research project, with a focus on medical doctors’ second language acquisition, the aim of the article is to problematise methodological issues in the process of collecting data. The model for data collection is a combination of participant observation and staged activities that provide opportunities for doctors to speak Swedish in a professional role and reflect on their language learning process. Data has been collected during visits to a medical Swedish language course in Poland and consists of role plays, interviews and focus group discussions. A second part of the data collection consists of recordings of some of the doctor’s real occurring interaction at work in the Swedish context.