This study has the purpose to identify the factors that cause satisfaction and dissatisfaction to the patients who are interns in hospitals which have agreements with "Sistema Unico de Saúde-SUS", based on the assistance rendered during the period of internment. The samples were constituted of 170 patients. To obtain the data, there was used a questionnaire containing 47 closed questions. The results obtained revealed several aspects that compromise the quality of the service rendered, such as: service doctors, nutrition, nurse and the environment. Thus, concludes there is dissatisfaction of the patients with the service offered by SUS.