After experiencing an emotional event, people either seek out others’ presence (social affiliation) or avoid others’ presence (social isolation). The determinants and effects of social affiliation are now well-known, but social psychologists have not yet thoroughly studied social isolation. This study aims to ascertain which motives and corresponding regulation strategies participants report for social isolation following negative emotional events. A group of 96 participants retrieved from memory an actual negative event that led them to temporarily socially isolate themselves and freely listed up to 10 motives for social isolation. Through semantic categorization of the 423 motives reported by the participants, we found that “cognitive clarification” and “keeping one’s distance” – that is, the need for cognitive regulation and the refusal of socioaffective regulation, respectively – were the most commonly and quickly reported motives for social isolation. We discuss the findings in terms of ideas for future studies aimed at clarifying the role of social isolation in health situations. (PsycINFO Database Record (c) 2018 APA, all rights reserved)