Since breast cancer is associated with high healthcare costs, hospitals prioritize reducing the length of stay (LOS). The aim of our study was to examine the process of women undergoing breast cancer surgical resection by measuring a performance parameter such as the LOS. We conducted a retrospective cohort analysis of patients discharged from Cardarelli Hospital in Naples, Italy, between 2019 and 2022. Postoperative LOS was analyzed using a multiple regression model to investigate the impact of clinical and demographic factors. Postoperative LOS was positively correlated with complications and emergency department admission, both of which significantly influenced it. Our findings suggest that complications and emergency department admission are useful indicators for identifying patients at risk for prolonged stays following breast cancer surgery. Based on this, corrective actions can be implemented to better allocate resources in breast cancer surgery, with the goal of optimizing the post-operative pathway.