Background: Nepal has a maternal mortality ratio of 186 per 100,000 live births, the second highest in South Asia. Institutional delivery, or giving birth in a medical facility with a skilled birth attendant, can prevent up to 16-33% of maternal deaths. Despite recent progress, Nepal’s institutional delivery rate is only 54%. As maternal mortality remains high and institutional delivery low, a transition from a biomedical to a psychosocial approach is needed, through which normative beliefs may be an entry point. The purpose of this study is to examine the relationship between descriptive norms and institutional delivery among mothers in Makwanpur, Nepal. Methods: This study uses baseline data from the Rejoice Architecture Project, a quasi-experimental study conducted in the Makwanpur District in Nepal in 2020. Female Community Health Volunteers (FCHVs) recruited 356 women from catchment areas of six health facilities across three Palikas (equivalent to municipalities) and administered oral surveys. Participants were eligible if they were 18 years or older, had a child younger than 2 years, and lived within the catchment area of a study site. Logistic regression was used to determine associations between descriptive norms and institutional delivery, controlling for antenatal care (ANC) visits, demographics, and interpersonal communication (IPC) with husband.Results: Approximately 30% of participants perceived most women in their community gave birth at home compared to medical institutions and nearly 65% gave birth in an institution during their last delivery. Logistic regressions showed an association between descriptive norms and institutional delivery after controlling for external factors such that on average, women who perceived institutional delivery to be most common had 3.18 greater odds of giving birth in an institution. Conclusions: Findings from this study support the notion that social norms relate to actual birthing behavior, specifically in the context of institutional delivery. These findings contribute to the growing body of literature relating to institutional delivery and offer insights for a potential norms-based approach for increasing rates of institutional delivery and reducing maternal mortality in developing countries.