Th is study aimed to examine the relationship between personality types and sense of humor and their association with teachers' performance improvement. Th is descriptive study followed a correlational design. Based on Morgan's table, a corpus of 201 elementary school teachers in Nehbandan was selected as a sample, using the stratifi ed random sampling method. Th e data collection tools were the Williams and Anderson Task Performance Scale (1991), the Eysenck Personality Inventory (1975), and the Moghimi and Ramazani Sense of Humor Questionnaire (2001). Th e results indicated that extraversion was signifi cantly and positively related to the teachers' performance and sense of humor and neuroticism was signifi cantly and negatively correlated with the teachers' performance and sense of humor. Moreover, a signifi cant and positive relationship was found between a sense of humor and the teachers' performance improvement. Furthermore, the results of regression analysis demonstrated that extraversion, neuroticism, and a sense of humor could predict the teachers' performance.