The quality assessment is a relevant issue in the strategic management of public health sector. The goal of this analysis is to investigate about the perception of the health quality system for long-term cancer patients. The data of interest have been collected during a survey conducted to long-term cancer patients who follow an oncological therapy in a Public Hospital. Exploratory Factorial Analysis (EFA) is developed and a Structural Equation Model (SEM) is proposed. The model describes the service quality, as perceived by the patients, which is influenced by four important factors such as tangible aspects, reliability, empathy (doctor-patient human relations) and hospital organization.