Objective: The study compared the in-hospital complications and related outcomes between women who underwent bilateral salpingo-oophorectomy at hysterectomy for benign diseases and those who had hysterectomy only. Methods: We conducted a population-based, retrospective cohort study using data from Taiwan's National Health Insurance program. Women who underwent concurrent bilateral salpingo-oophorectomy at hysterectomy for benign indications (n=34,509) were compared with those who had hysterectomy only (n=176,305). Separate models were estimated to account for the effect of baseline comorbid condition, age, and hysterectomy approach on the relationship between bilateral salpingo-oophorectomy and study outcomes. A secondary analysis was also performed to evaluate the association of inpatient readmission within 30 days and complications among women who underwent bilateral salpingo-oophorectomy. Results: The addition of a bilateral salpingo-oophorectomy to hysterectomy was associated with a lower risk of surgical complications, a longer length of hospital stay, and an increased risk of inpatient readmission within 30 days. Among women who underwent bilateral salpingo-oophorectomy, women with complications were also more likely to require inpatient readmission within 30 days than those without complications. Our data also suggested that bilateral salpingo-oophorectomy was not associated with an overall risk of medical complications, with the exception of urethral obstruction. The relationships remained even after adjustments by age, surgical indications, hysterectomy approach, and health-related risk factors, such as baseline comorbid condition and status of any prior catastrophic illness. Conclusions: Bilateral salpingo-oophorectomy at hysterectomy for benign conditions is not associated with an increased risk of in-hospital complications.