The Lean Six Sigma (LSS) methodology is a structured approach to processes that is also brought to the healthcare sector. The correct adoption of the LSS methodology guarantees the improvement of the quality of products or services, eliminating defects (Six Sigma) and with reduction of waste, and the creation of value for the customer (Lean). The aim of the work is to use this valid management approach to analyze these factors in a dramatic historical period for health care such as the COVID-19 pandemic. In this study, the DMAIC cycle was used to study the impact of COVID on the length of stay (LOS) in the gynecology department of the Evangelical “Betania” hospital in Naples, Italy, of patients who underwent a cesarean section (CS). The study using inferential statistical tools revealed a general reduction in LOS, as well as in the number of women giving birth by cesarean section. The containment actions and new protocols adopted in the COVID-19 era showed, in the Control phase, a reduction in LOS for the entire sample observed. An interesting finding showed a reduction in LOS and variability in women over 35 and in standard conditions, i.e., uncomplicated deliveries without comorbidities. This paper analyses in a structured way the impact of COVID-19 on women who were admitted for CS in an Italian hospital. It shows how the protocols adopted improved the organization and reduced the LOS and its variability.