Reflection in its social notion has mainly been studied in a temporary way of actors stepping back to question taken-for-granted assumptions of organizing. Drawing on a single case study of introducing lean production to a hospital’s emergency care unit (ECU) over a period of 23 months, we aim to explore how reflection works in organizations given the ongoing flux of organizing and understanding reflection as a social phenomenon. We identify four practices that together make up collective reflection in our case and whose activities differ according to where joint reflection takes place, what it is mainly about, who is involved and when it occurs. These insights complexify our current understanding of collective reflection in four ways: First, reflection in its social notion contains several activities, which together ensure communicative availability that cannot be taken as given in organizations. Second, collectively reflecting in organizations calls for taking its value creation into account (reflecting from within or from outside the organizational value creation). Third, collective reflection encompasses two different orientations regarding the organizational value creation (reflecting in order to keep day-to-day business running and/or to improve the conditions for the value creation). Fourth, we empirically find that the reflection activities follow two different temporal rhythms (ad-hoc responses to a situation at hand or pre-planned regular activities). With these insights we contribute new nuances to our understanding of how collective reflection works in organizing.