Background: To maintain an optimal nutritional status and immunological function in PLHIV, a diet with adequate nutrients is of utmost importance. This is a major challenge among poor populations in developing worlds like Nigeria, where malnutrition and food insecurity are endemic. This study aimed to assess the type of regular diet consumed and assess the impact of supplementation of the diet with Moringa oleifera Lam. leaves on the nutritional status and CD4 cell counts of PLHIV that are on ART in Nigeria. Method: A double-blind, randomized trial was conducted. Two hundred consented patients were randomly allocated to either the Moringa oleifera Lam. group (MOG) or control group (COG). The FAO individual dietary diversity questionnaire was used. The regular diets of participants at baseline and six months were monitored. The measurements of weight, BMI, MUAC, and CD4 cell counts were obtained from baseline to six months of Moringa oleifera Lam. leaves supplementation. Results: One hundred and seventy-seven patients completed the six-month follow-up (89 MOG versus 88 COG). At both baseline and sixth month, the foods most commonly consumed by the participants in both MOG and COG were cereals, spices and condiments, oils, fats and palm oil, and dark green vegetables. At baseline, significantly higher consumption of legumes, nuts & seeds (p= 0.001) was observed in the MOG and higher consumption of other vegetables (p= 0.024) in COG. Consumption of cereals, roots, and tubers was significantly higher (p= 0.024; 0.045) in the COG in the sixth month. In both groups, participants were in the medium or low dietary diversity tercile. Throughout the study period, all the nutritional status variables observed were not significantly different between the two study groups [(p > 0.0001); weight; p=0.5556; BMI; p=0.5145; MUAC; p=0.6456]. Over the study period, the treatment by time interaction shows a significant difference in CD4 counts by treatment group (p<0.0001) and an estimate of fixed effects 10.33 folds greater in the MOG than COG. All tests were conducted at 95CI. Conclusion: This study revealed that a diversified diet is a major nutritional problem. Supplementation of regular diet with Moringa oleifera Lam. leaves did not affect the nutritional status but could improve the immune response of PLHIV that are on ART Clinical Trial Registration Details: Pan African Clinical Trial Registry (identification number PACTR201811722056449). Funding Information: This study has been funded by the Department of Science and Innovation of South Africa (Contract No. DST/CON 0196/2011) and the College of Health Sciences, University of Kwazulu- Natal, Durban, South Africa. Declaration of Interests: The authors declare they have no conflict of interest. Ethics Approval Statement: The study was reviewed and approved by the ethics committee of Aminu Kano Teaching Hospital (AKTH) Kano State, Nigeria (reference number NHREC/21/08/2008/AKTH/EC/2012), and the Biomedical Research Ethics Committee of the University of Kwazulu-Natal, Durban, South Africa, (reference number BFC294/16). This study was conducted in compliance with the principles enunciated in Helsinki's Declaration [24]. All the study participants provided signed written informed consent or thumbprint if unable to sign.