Variations in systemic lupus erythematosus (SLE) clinical manifestations, serologies and outcomes have been related to gender differences. However, these associations have not been evaluated in Puerto Ricans. A cross-sectional study was performed in a cohort of 235 Puerto Rican SLE patients. Clinical variables, autoantibodies, SLICC/ACR damage index and mortality rate were determined. Of the 235 SLE patients, 12 (5%) were males. Male and female patients were similar with respect to age, disease duration and follow up. Men were more likely to have pericardial effusion (41% vs 5%, p<0.01), pleural effusion (58% vs 10%, p<0.01), proteinuria (>0.5 g/24 hr) (58% vs 24%, p=0.02), renal insufficiency (42% vs 11%, p<0.01) and end-stage renal disease (33% vs 6%, p<0.01) than women. Anti-Sm antibodies (60.0% vs 13%, p<0.01) and anti-snRNP antibodies (56% vs 21%, p=0.03) were more prevalent in men. SLICC/ACR mean damage index (2.7 +/- 2.7 vs 1.0 +/- 1.6, p<0.01) and mortality rate (25% vs 4.5%, p=0.02) were higher in men. In conclusion, male SLE patients of this cohort had higher prevalence of serositis and renal involvement than women. They also had a poorer outcome, presenting higher disease damage and mortality.