The Department of General Medicine treats patients remotely, the critical care unit, or using expertise in other wards who have a variety of acute or chronic diseases. The length of stay (LOS) is an effective instrument for keeping track of subjects and assessing the effectiveness and caliber of the services provided. The length of stay in hospitals can vary depending on the specific condition or procedure. It can range from a few hours or days to several weeks or even months for more complex cases or treatments. The duration of hospital stays is often determined by factors such as the severity of the illness or injury, the requirements for specialized care, recovery time, or the quality of the healthcare services. The analysis aim was for providing LOS for all subjects hospitalized to the General Medicine Department at the University Hospital Federico II of Naples. For this study the Machine Learning analysis was employed. Data show that that more input variables relating to clinical factors should be included in future investigations, along with a larger patient dataset.