OBJECTIVES: To determine the cost effectiveness of direct monthly supply of HAART (Highly active anti retroviral therapy) medications at the AIDS center. METHODS: We analyzed 385 HIV patients, mostly (90%) immigrants from Africa (HIV subtype C) that were treated with HAART for more than one year prior to the initiation of the study.  During the first two years of the study, all patients received HAART prescriptions and the medications were supplied by local pharmacies.  Thereafter (next 2 years) all patients received their medications, monthly, by a nurse (on a part-time job basis) at our AIDS center.  Compliance, immunological (CD4) and virological (VL) outcome between the two study periods (modes) were compared.  RESULTS: The mean age of our patients, 48% males, at time of study initiation was 35±13 (mean ±SD) years. The mean time from HIV diagnosis was 7.3±4.1 years.  Following the first 2 years, 75% of the patients attended more then 90% of scheduled visits with 57%  treatment adherence (>90% of prescriptions).  The mean CD4 count at the end of this period was 324.8±220.9 cell/mcl (66.7% > 200 cells/mcl). Virological failure (VL>40 copies/ml) was observed in 53% (mean VL 182,918±834,916 copies/ml) of the treated patients.  As a result of our intervention (two years of direct HAART supply), visits and treatment compliance increased, significantly (p<0.001), to 90% and 84%, respectively.   Concomitantly the CD4 cell counts increased to 470±266 cell/mcl (p=0.24 compared to the first study period) with 83.6%   CD4 counts >200cells/mcl (p<0.001). A low rate of virological failures (28%; p<0.001; mean VL 15,068±73,382 copies/ml; p<0.001) was observed. CONCLUSIONS: Direct monthly supply of HAART medications at the HIV center is a very low cost mode which significantly improves patient's adherence as well as immunological and virological outcome.