The aim of the present study was to predict critical thinking based on demographic variables and personality dimensions of teachers. To ensure, 350 questionnaires were administered among teachers in Tehran. Random sampling method was used to select the sample. First, the reliability coefficient was calculated by internal consistency method for the personality dimensions and critical thinking questionnaire. The results show that the reliability coefficients of the personality traits and critical thinking questionnaire are desirable and satisfactory. After examining the internal consistency, the validity of the questionnaire was examined. For this purpose, the factor analysis method using the principal components method was used. The KMO value for the NEO personality questionnaire and the critical thinking questionnaire was higher than 0.935 and the level of significance of the Bartlett spherical characteristic for both questionnaires was less than 0.01. Factor weights estimated by the maximum likelihood method indicated that all indices have a factor load greater than 0.35 and the root error value of the mean squared RMSEA approximation is close to 0.07. Therefore, it can be concluded that in the present study, the research tools have a good fit. Finally, multivariate regression analysis was used to predict teachers' critical thinking through demographic variables and personality traits. The results showed that when the variable Predictor is only an extroverted personality trait. The value of R was 0.480, while with the addition of variables of conscience, flexibility, gender, education, neuroticism, pleasantness as the predictor variable, the value of R increased to 0.606. Has found.