Self-criticism is a trait associated with increased psychopathology, but self-criticism is also a personality state reflecting an action that people do in moments of time. In the current study, we explored factors associated with heightened self-criticism in daily life. Participants (N = 197) received five random prompts per day for one week on their mobile phones, where they reported their current affect (negative and positive affect), willpower self-efficacy, distress intolerance, degree of support and criticism from others, current context (location, activity, (...) hunger, tiredness) and momentary self-criticism. We first demonstrated that self-criticism varies over time and across contexts, and is associated with heightened trait self-criticism. Then, using multilevel modelling, we explored the contextual factors associated with greater self-criticism. We found that self-criticism was higher when people were at home, and more tired. We also found higher self-criticism to be associated with greater negative and lower positive affect, greater distress intolerance, lower willpower and greater perceived criticism from others. In addition, self-criticism predicted subsequent distress intolerance, willpower and positive affect in lagged analyses. This study provides evidence that both environmental and psychological factors are associated with the dynamics of self-critical thoughts. (shrink)