Research suggests that perfectionism can vary across contexts, but what explains this variation? Across two studies (total N=783), we examined whether frustration or satisfaction of a person’s basic psychological needs (for autonomy, competence, and relatedness) predicts perfectionism within domains (Study 1) and over time (Study 2). Consistent with our hypothesis, people tended to be more self-critical in domains where their needs were frustrated. Further, being in a context where needs are frustrated tended to exacerbate self-critical perfectionism over time. Exploratory analyses provided mixed evidence for the association between need satisfaction and personal standards. Notably, however, being in a context where needs are satisfied decreased self-critical perfectionistic tendencies over time. By better understanding when people are likely to exhibit maladaptive perfectionistic tendencies that undermine mental health and well-being, researchers can develop targeted interventions focusing on creating need supportive environments and/or helping people adaptively cope in situations where their needs are frustrated.