© 2018, American College of Rheumatology Objective: Systemic lupus erythematosus (SLE) predominantly affects women. Clinical phenotype and outcomes in SLE may vary by sex and are further complicated by unique concerns that are dependent upon sex-defined roles. We aimed to describe sex differences in disease-specific quality of life (QoL) assessment scores using the Lupus Patient-Reported Outcome (LupusPRO) tool in a large international study. Methods: Cross-sectional data from 1,803 patients with SLE on demographics, self-identified sex status, LupusPRO, and disease activity were analyzed. The LupusPRO tool has 2 constructs: health-related QoL (HRQoL) and non-HRQoL. Disease activity and damage were evaluated using the Safety of Estrogens in Lupus Erythematosus National Assessment version of the Systemic Lupus Erythematosus Disease Activity Index and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index, respectively. Nonparametric tests were used to compare QoL and disease activity by sex. Results: A total of 122 men and 1,681 women with SLE participated. The mean age was similar by sex, but the damage scores were greater among men. Men fared worse on the non-HRQoL social support domain than women (P = 0.02). When comparing disease and QoL among men and women ages ≤45 years, men were found to have greater damage and worse social support than women. However, women fared significantly worse on lupus symptoms, cognition, and procreation domains with trends for worse functioning on physical health and pain-vitality domains. Conclusion: In the largest study of a diverse group of SLE patients, utilizing a disease-specific QoL tool, sex differences in QoL were observed on both HRQoL and non-HRQoL constructs. Although men performed worse in the social support domain, women (especially those in the reproductive age group) fared worse in other domains. These observations may assist physicians in appropriately addressing QoL issues in a sex-focused manner.