Perfectionism is a personality trait that plays an important role in understanding human behavior and functioning. There has been a focus on the negative aspects and outcomes of perfectionism, and less is known about whether and how perfectionism relates to adaptive characteristics of personality and normal functioning. We investigated associations between different aspects of perfectionism and psychological well-being in two studies by determining the role of dispositional flow and personality traits in this relationship. In Study 1, participants completed questionnaires for perfectionism, psychological well-being and flow. In Study 2, personality traits from the HEXACO model of personality were additionally measured. We found that psychological well-being had a positive correlation with conscientious perfectionism and a negative correlation with self-evaluative perfectionism. Flow mediates the relationship between conscientious perfectionism and psychological well-being. There was no correlation between self-evaluative perfectionism and dispositional flow. After controlling for relevant personality traits, dispositional flow remains the mediator between conscientious perfectionism and psychological well-being, but the relation becomes negative. Implications for the understanding of how different components of perfectionism are related to psychological well-being and how flow experience contributes to this relationship are discussed.