This research aimed to investigate the prediction of marital instability based on emotional maturity and attachment needs. The research method was descriptive-correlational. The statistical population consisted of married students at Islamic Azad University, Shiraz Branch, during the academic year 1402-1403, from which 200 individuals (75 men and 125 women) were selected as samples using the convenience sampling method. The research instruments included Edwards et al.'s Instability Questionnaire (1987, MII), Samani and Sohrabi's Attachment Needs Questionnaire (2022, MANS), and Singh and Bhargava's Emotional Maturity Scale (1990, EMS). The data were analyzed using a multiple regression test. The findings showed that the variables of emotional maturity and attachment needs were significantly (P<0.001) able to predict marital instability, such that the amount of variance explained for marital instability by attachment needs and emotional maturity was 66 percent in total. According to the results obtained, it is suggested that premarital counseling should examine the level of emotional maturity and attachment needs of couples and hold workshops to raise their awareness of these factors.