Treatment of HIV-infected persons including nutritional management is a major concern in Africa and in particular in the Central African Republic (CAR). This six-month randomized prospective longitudinal study was carried out at the Friends of Africa Center that was a facility for comprehensive management of persons infected and affected by HIV in Banqui, CAR. The purpose of the study was to assess the impact of spirulina supplement on clinical and laboratory findings in HIV-infected patients who were not indications for ARV treatment. A total of 160 patients were randomly assigned to two groups. Patients in group 1 (n=79) received 10 grams of spirulina per day on a regular basis while patients in group 2 (n = 81) received a placebo. In addition patients in both groups received dietary products supplied by the World Food Program (WFP). Follow-up of the 160 patients at three and six months showed that 16 patients had been lost from follow-up and 16 had died, with no difference in distribution between the two groups. A significant improvement in the main follow-up criteria, i.e., weight, arm girth, number of infectious episodes, CD4 count, and protidemia, was observed in both groups. No difference was found between the two groups except with regard to protidemia and creatinemia that were higher in the group receiving spirulina supplement. From a clinical standpoint results were less clear-cut since the Karnofsky score was better in the group receiving spirulina than in the group receiving the placebo at 3 months but not at 6 months and fewer patients presented pneumonia at six months. Further study over a longer period will be needed to determine if spirulina is useful and to evaluate if higher doses can have beneficial nutritional and immunitary effects without adverse effects, in particular renal problems.