The aim of the present study was to investigate the effect of correcting perfectionist cognitive bias on distress tolerance and procrastination of perfectionist students. The current study, which was a semi-experimental study with a pre-test-post-test design with a control group, was conducted among university students in Dashtestan. The researchers invited the students to complete the online questionnaire of perfectionism by informing through virtual space. 68 of the 328 students who completed the multidimensional perfectionism scale (MPS) of Frost (1990) were identified as perfectionist students, and 40 of them were randomly selected and using the random assignment method in two The experimental and control groups were placed. The students of the experimental group participated in the weekly meetings to correct the perfectionistic cognitive bias in person during 8 weeks between November and December 2021. The findings showed that correcting perfectionistic cognitive biases increases students' distress tolerance (p<0.01), but no significant change was observed in students' procrastination (p<0.85). Considering the characteristics of perfectionism and also the psychological damages caused by it in students, the implementation of interventions aimed at reducing perfectionist biases can play an effective role in preventing these damages.