Aim: Sexual relation is an important and sensitive subject among human beings. A life domain that has received very little attention is patients' satisfaction with their sex life, also called sexual satisfaction. Physical illnesses and mental disorders affect sexual satisfaction. The aim of this project was to compare sexual satisfaction among psychiatric, internal medicine patients and healthy controls. Methods: This is a cross-sectional study. Statistical population consisted of all the patients who referred to the clinic during the spring of 2017 as psychiatric and internal medicine outpatients who were referred to Emam Reza and Motahari policlinic affiliated to Shiraz University of Medical Sciences (SUMS). 200 patients with psychiatric disorder, 200 patients with internal disease, and 200 healthy controls were selected using convenience sampling to participate in the study. They filled out demographic information questionnaire and Larson Sexual Satisfaction (LSS). Findings: The groups differed significantly in variance analysis in terms of sexual satisfaction (F=29.27, p= 0.001), compatibility (F=5.77, p= 0.003), quality (F=23.79, p= 0.001), and attitude (F=15.26, p= 0.001). Discussion: The results of the study indicated a lower rate of sexual satisfaction in the psychiatric patients compared to internal medicine patients and healthy controls.