Marital forgiveness is considered an important psychological process in managing conflicts and repairing emotional damage in marriage. The aim of this study was to develop and evaluate a native marital forgiveness scale based on the social and psychological model of McCullough et al. (1998). The study consisted of two stages: the first stage with 351 participants for exploratory factor analysis (EFA) and the second stage with 443 participants for confirmatory factor analysis (CFA), convergent and criterion-based validity, and reliability analysis. The scale development process included a literature review, a qualitative study with interviews of Iranian participants from different cultures, item generation, content-based validity, and scale administration. EFA analysis identified four main factors including “avoidance”, “tendency for revenge”, “conditional forgiveness”, and “unconditional forgiveness”, which explained a total of 61.79% of the variance. (CFA) confirmed the four-factor structure and the second-order model and showed that the scale has good fit, convergent validity, criterion-based validity, and high reliability (α=0.93). The results showed that marital forgiveness is associated with a decrease in avoidance and desire for revenge and an increase in positive relationship behaviors, and the presented scale is considered an appropriate tool for measuring the willingness to forgive one's spouse's transgressions in Iranian-Islamic culture.