A six month study was done to investigate the efficacy of Plumpy nut in improving nutritional status of 108 HIV positive pregnant women aged between 15-49 years and who were attending Private and Government Reproductive and Child Health (RCH) clinics at Temeke Municipality. Seventy three (73) subjects received Plumpy nut made from Nutriset, France and thirty five (35) subjects received maize meal made from Azam, Tanzania. The subjects who received Plumpy nut, consumed a sachet of 92 g of Plumpy nut per day and those who received maize meal, receive a 250 g of maize meal per day. Physical measurements of weight, total body fat and MUAC, bio-chemical measurement (hemoglobin concentration) and morbidity information were taken monthly; height was taken at baseline only. Infant’s weight was taken at birth. A 24-hr dietary recall technique was used to collect information on food consumption at baseline and at the end of the study. Significant differences were observed in birth weight and mean daily intakes for energy and fat between the subjects who received Plumpy nut and those who did not receive it. Subjects who received Plumpy nut give birth to heavy babies (p=0.000), higher intakes of energy (p=0.028) and fat (p=0.000). However, the differences in maternal weight, MUAC, Total body fat and Haemoglobin concentration between subjects during this study were not significant. This study concludes that, the plumpynut product is effective in improving nutritional status of HIV positive pregnant women and their infants. The Government and non- governmental organizations are called upon to improve the nutritional status of pregnant women living with HIV/AIDS by supporting them through nutritional based initiatives if they are to produce healthy babies and breastfeed successfully.