Day-to-day life is inundated with attempts to control emotions and a wealth of research has examined what strategies people use and how effective these strategies are. However, until more recently, research has often neglected more basic questions such as whether and how people choose to regulate their emotions (i.e. emotion regulation choice). In an effort to identify what we know and what we need to know, we systematically reviewed studies that examined potential determinants of whether and how people choose to regulate their emotions. Eighteen determinants were identified across 219 studies and were categorised as being affective, cognitive, motivational, individual or social-cultural in nature. Where there were sufficient primary studies, meta-analysis was used to quantify the size of the associations between potential determinants and measures of whether and how people choose to regulate their emotions. Based on the findings, we propose that people's decisions about whether and how to regulate their emotions are determined by factors relating to the individual doing the regulating, the emotion that is being regulated, and both the immediate situation and the broader social context in which the regulation is taking place.