Purpose The purpose of this paper is to discuss methodological issues concerning the use of video observation of a single lesson as a supplement to interviews when studying teachers’ practice and competencies.Design/methodology/approach Using a Danish follow-up study focused on teachers’ practice as a jumping-off point, the authors address both opportunities and challenges when triangulating interviews with video observations of a single lesson. The discussion is structured around the four challenges when using video observations presented by Derry et al. (2010), namely selection, technology, analysis and ethics.Findings Based on experiences from the follow-up study, the use of video observations for triangulation has the potential to nuance the meanings ascribed to teachers’ practice. This approach entails productive challenges that can support the more nuanced and diverse perspectives on teachers’ practice if used proactively.Originality/value Although there is a wide body of literature on conducting interviews and observations when studying teachers’ practice, the use of a combination of interviews and video observations is seldom addressed. This paper presents concrete experience of how to capture different aspects of teachers’ practice by triangulating data generated from interviews and from video observations in a research design with limited resources. The authors discuss what to consider when planning and conducting video observations of a single lesson as part of an interview-based study.