<p>The preference for sons has been well documented in Nepal and is directly linked to reproductive health outcomes, such as the use of contraception. This paper examines the patterns of contraceptive use in Nepal and investigates the influence of son preference on contraceptive use among women with only daughters compared to those with only sons. The study analyzes data from the four most recent Nepal Demographic and Health Surveys (NDHS). Use of traditional contraceptives increased in both groups over the survey years but was not associated with the number of children for either group of women. In contrast, use of modern contraceptives was consistently higher among women with only sons than among those with only daughters across all survey years, indicating that women with only sons were more likely to use modern contraception. Fertility preference was another predictor of modern contraception use in both groups. Socioeconomic factors—such as women’s and husbands’ education, place of residence, caste and ethnicity, wealth status, and working status, also showed varying associations with modern contraceptive use across the both groups over the four survey periods. Despite declining fertility rates and improvements in women’s socioeconomic status in Nepal, son preference remains a key determinant for the use and non-use of any modern contraceptive methods for fertility regulation. Therefore, family planning programs must address issues of gender inequality.</p>