Objective: The objective of this study is to examine the detailed pregnancy and neonatal outcomes of women without male partners undergoing intrauterine insemination (IUI) compared to women with male partners. Methods: This is a retrospective cohort study of all patients who completed an IUI cycle from 2017 to 2023. 2414 cycles were included in the study: 149 cycles for women without male partners (including single and lesbian women) and 2265 cycles for women with male partners. Primary outcomes were the rates of clinical pregnancy, miscarriage, and live birth. Secondary outcomes were obstetric complication rates and neonatal outcomes. Results: Women without male partners undergoing IUI were significantly older than the reference cohort (median age 42 years versus 38 years, p < 0.0001). 84.1% of women without male partners did not have a diagnosis of the common causes of female infertility. Both cohorts had similar cycle characteristics and number of IUI cycles until pregnancy and live birth. The mean clinical pregnancy rate per cycle for women without male partners was 11.4% versus 12.5% for the reference group (p = 0.56), and the mean live birth rate was 8.1% versus 8.2% (p = 0.95). Multiple pregnancy, cumulative pregnancy, and clinical miscarriage rates were also similar. Similarities persisted after adjusting for confounders: age, BMI, race, and infertility diagnosis. Importantly, there were no statistically significant differences in obstetric complications (such as hypertensive disorders of pregnancy, gestational diabetes, placental disorders) and neonatal outcomes. Conclusions: Compared to women with male partners undergoing IUI, women without male partners had similar rates of clinical pregnancy (per cycle and cumulative), miscarriage, and live birth; there were no significant differences in obstetric complications or neonatal outcomes.