The racial diversity and gender distribution of HIV-infected patients make it essential to confirm the safety and efficacy of raltegravir in these populations. A multicenter, open-label, single-arm observational study was conducted in a diverse cohort of HIV-infected patients (goals: ‡25% women; ‡50% blacks in the United States), enrolling treatment-experienced patients failing or intolerant to current antiretroviral therapy (ART) and treatment-naive patients (limited to £20%). All patients received raltegravir 400mg b.i.d. in a combination antiretroviral regimen for up to 48 weeks. A total of 206 patients received study treatment at 34 sites in the United States, Brazil, Dominican Republic, Jamaica, and South Africa: 97 (47%) were female and 153 (74%) were black [116 (56%) in the United States]. Of these, 185 patients were treatment experienced: 97 (47%) were failing and 88 (43%) were intolerant to current therapy; 21 patients (10%) were treatment naive. Among treatment- intolerant patients, 55 (63%) had HIV-1 RNA<50 copies/ml at baseline. Overall, 15% of patients discontinued: 13% of men, 18% of women, 14% of blacks, and 17% of nonblacks. At week 48, HIV RNA was <50 copies/ml in 60/94 (64%) patients failing prior therapy, 61/80 (76%) patients intolerant to prior therapy, and 16/21 (76%) treatment-naive patients. Response rates were similar for men vs. women and black vs. nonblack patients. Drug- related clinical adverse events were reported by 8% of men, 18% of women, 14% of blacks, and 9% of nonblacks. After 48 weeks of treatment in a diverse cohort of HIV-infected patients, raltegravir was generally safe and well tolerated with potent efficacy regardless of gender or race.