Gender role attitudes play an important role in shaping women’s fertility patterns. The present study aimed to examine the relationship between gender role attitudes and fertility behavior. This quantitative study employed a survey design and was conducted among mothers with a spouse in Shiraz, Iran. A multistage cluster sampling method was used to recruit 245 participants. The findings showed that the mean actual fertility of mothers with a spouse was 1.85 children. Egalitarian and feminine gender role attitudes were associated with lower actual fertility, whereas masculine gender role attitudes had a weak positive association with fertility. Older age among mothers with a spouse was associated with a higher number of children. Higher educational attainment and being employed were significantly associated with lower fertility. Multivariable regression analysis further showed that egalitarian and feminine gender role attitudes were significant predictors of women’s fertility decisions. Overall, the findings indicate that changes in women’s gender role attitudes in the context of broader social transformations are associated with their fertility patterns. However, these findings do not imply that gender equality should be restricted or that women’s social status should be undermined. Rather, they suggest that population policies should adapt to changing patterns of women’s lives and evolving gender role attitudes. Accordingly, alongside economic support and fertility-related incentives, population policies could focus on creating conditions that enable women to reconcile social participation, family roles, and childbearing. Such an approach could facilitate informed fertility choices under changing social conditions without reverting to traditional gender-role patterns.