Introduction: Marital adjustment is one of the most important factors in determining the stability and durability of marital relationship. Therefore, this study was conducted to investigate individual factors in marital adjustment. Materials and Methods: This research was conducted qualitatively using thematic analysis method. The sampling was purposeful and saturated and the data were obtained from 16 married couples who had been married for at least 7 years. Semi-structured interview method was used to collect data. Results: To analyze the data MAXQDR 2018 software has been used. After analyzing the content of the data, five main categories were obtained, which are: interpersonal factors (sexual satisfaction, mutual understanding, criticism, forgiveness and self-sacrifice) in order of importance. Intrapersonal factors (self-worth, positive attitude towards others). Emotional factors (feeling happy, expressing anger and worry, resilience). Personality factors (extraversion, responsibility, sociability). Social intelligence (accepting and recognizing one's feelings, acceptance). And recognizing the feelings of others, behavioral balance). Conclusion: Marital adjustment is more dependent on individual factors that occur during life.