The advent of the Covid-19 pandemic in 2020 implied the introduction of new management rules into all company processes with the aim of combating the spread of the virus. These enforcement actions defined first at central level by the Ministry of Health and then adopted by each company and entity, have had a strong impact especially on healthcare processes in terms of management of the patient and his activities. By introducing the LOS as an efficiency parameter of hospital departments, with reference to patients hospitalized in the urology department of the Cardarelli Hospital in Naples in 2019 (without pandemic) and 2020 (during the pandemic), in this study it is evaluated through the Lean Six Sigma (LSS) methodology, the impact of actions to combat the pandemic on hospital performance, i.e. on LOS. The statistical analysis, carried out to evaluate the possible differences, was carried out using the Jamovi software. All phases of the DMAIC cycle, namely Define, Measure, Analyze, Improve, and Control, were analyzed in the work. Analysis of LOS also showed that this value increased in the year 2020 for male patients with comorbidities. In fact, the statistically significant variables were as follows: male patients, without comorbidities and under the age of 65.