Purpose: The purpose of this study is to explore how lesson study (LS) can be transitioned to an online mode, with the purpose to derive recommendations for performing online LS while being loyal to the defining elements of a face-to-face LS. Design/methodology/approach: A theoretical analysis into the core components and procedures of LS resulted in five big ideas that capture essentials of LS. Using these big ideas, constraints were derived for online LS and a pilot online LS was performed. Data were collected on the process and team members' reflections. The experience in the pilot was mapped against the outcomes of the theoretical analysis. Findings: Setting up close collaboration and the observation of the online lesson appeared to be the most challenging issues. A set of recommendations in the form of do's and don'ts was derived from the experience. Practical implications: The set of recommendations can be applied by practitioners who face the challenge of performing LS in an online environment, and can serve as a start for further research in online LS. Originality/value: The original contribution of the article is the combination of the theoretical analysis of LS combined with the practical experience in the pilot. This gives rise to a framework that can help understanding LS in general and online environments in particular.