The present study aims to investigate the factors influencing marital stability, considering the mediating role of we-ness. The research method was descriptive-correlational study employed structural equation modeling (SEM) and and the statistical population was all married individuals residing in Varamin and Pishva cities in 2025. Using a purposive sampling method, 388 participants were selected. Data was collected using the following standardized questionnaires: the Marital Instability Index (MII; Booth, Johnson & Edwards 1980), the Bell Object Relations Inventory (BORI; Bell, 1985), the Ego Strength Scale (ESS; Besharat, 2017), and the We-ness Questionnaire (WQ; Vedes et al., 2015). Data analysis was performed using structural equation modeling and correlation tests. The final model demonstrated an acceptable fit to the data, with indices such as RMSEA = 0.076 and CFI = 0.899. All observed variables loaded significantly onto their respective latent constructs, with factor loadings exceeding 0.3 (p < .05). In addition, the mediating role of we-ness in the indirect relationship between primary object relations and ego strength with marital stability was confirmed. The results highlight the importance of primary object relations and ego strength, as well as the key role of we-ness as an influential mechanism on marital stability. Consequently, designing educational interventions for parents (particularly mothers) focusing on primary object relations and fostering a sense of we-ness could contribute to enhanced marital durability.