Sexual satisfaction is an important aspect of overall life satisfaction. The Male Sexual Quotient (MSQ) was designed to provide a versatile, user-friendly instrument to measure various aspects of male sexual function and satisfaction.Assess responses to the MSQ in men with sexual dysfunction (SD).Items for inclusion in the MSQ were developed through interviewing 612 randomly recruited men in São Paulo, Brazil, about factors considered to influence sexual quality of life. Validation of the MSQ was conducted in two phases in men with and without SD.The correlation between patients' total MSQ score and scores on the Sexual Health Inventory for Men (SHIM).The resulting MSQ questionnaire contains 10 items that address sexual function and satisfaction and is scored on a 100-point scale, with higher scores indicating greater sexual function and satisfaction with such function. Patients' scores on the MSQ were positively correlated with scores on the SHIM (r = 0.86; P < 0.0001). Scores on MSQ item 8, which assesses ejaculatory control, indicated that 46% of patients may have premature ejaculation (PE). The mean time for patients to complete the MSQ was 11 minutes.The MSQ is a brief, comprehensive, and easily self-administered tool designed to help men identify aspects of their sexual experience that could be improved through partner dialogue, physician consultation, and appropriate treatment. MSQ scores correlated well with SHIM scores, and scores were inversely related to the severity of erectile dysfunction or PE and other male SDs. These preliminary findings suggest that the MSQ possesses good convergent validity. Nearly half of men reported problems with ejaculatory control, indicating an association between PE and other SD. Further validation of the MSQ in a double-blind trial is needed. The MSQ may aid in decision making for the treatment of SD.