Canadian sociologist Dorothy Smith’s institutional ethnography (IE) is an ontology of the social that conceptualises ‘life as usual’ as the ongoing coordination of people’s actions across diverse sites. Popular in the health sciences and human service professions as a research strategy for understanding and explicating problematics of everyday life, it is slowly gaining traction as a critical research approach for library and information science (LIS). This article introduces IE and provides an overview of its central tenets. It outlines ways in which institutional ethnographers identify research problematics and collect and analyse data. The article concludes with three illustrations of how institutional ethnography has been used to map the linkages among activities and institutional processes, ultimately revealing how it can contribute to a critical understanding of library and information science practices and scholarship.