Objective: To assess the effect of oral health education on knowledge and oral health seeking behaviour of persons living with HIV/AIDS (PLWHA).Methods: Quasi-experimental study design conducted among 195 Persons living with HIV/AIDS attending two Comprehensive Care Centres (CCC) at the Kenyatta National Hospital (intervention group) and Mbagathi district hospital (non-intervention group) in Nairobi Kenya. The participants were selected using systematic random sampling method and data collected using a questionnaire. Data was collected at baseline, at three months (review 1) and at six months (review 2).Results: There was a significant change in oral health knowledge for KNH participants. However, no significant change in oral knowledge was recorded for MDH participants. The proportion of participants who brushed their teeth at least twice a day increased significantly from 52% to 88% for KNH. The proportion of those who had brushed the previous evening increased from 47% to 83.2%. There was no significant change in the proportion brushing at least twice a day among the non-intervention group. There was a significant association between change in knowledge and change to brushing at least twice a day among the intervention group.Conclusion: Oral health education led to improved oral health knowledge and oral hygiene practices among PLWHA