Abacavir is one of the first-line drugs used to treat HIV infection in paediatric patients in Zambia, whose use in children has not been widely published. This study compared the virologic response of abacavir given as part of a once-daily regimen with the response when given as part of a twice-daily regimen. A total of eighty-two children aged two to twelve years currently receiving antiretroviral therapy at the Paediatric Centre of Excellence, University Teaching Hospitals, Lusaka, Zambia, were observed in the study. This was a prospective cohort study. All the children were initially on twice daily abacavir containing regimen with lamivudine twice daily and efavirenz once daily, with 40 maintained on this regimen by the attending clinician and 42 switched to once-daily abacavir, lamivudine and efavirenz by the attending clinician. Profiles were obtained for each child to compare viral load at baseline and week 24. Data was analysed using Stata Version 16.The proportion of children with undetectable viral load in the once-daily group at twenty-four weeks was 64.3 per cent compared to 72.5 per centin the twice-daily group. Twice-daily dosing reduced the odds of achieving an undetectable viral load by about 59 per cent, while being male reduced the odds of achieving an undetectable HIV viral load by 19.6 per cent. Baseline haemoglobin, creatinine, or alanine transferase levels were not predictors of viral load suppression.The study suggests that once-daily dosing of an abacavir-containing regimen achieved a lower viral suppression rate when compared to twice-daily dosing. It is recommended that once-daily dosing of abacavir containing regimen should be considered as a dosing option for Zambian children living with HIV.