Background: After birth, infants infected with human Immunodeficiency virus or not are always at risk if exclusive breast feeding (EBF) is not practice since mother’s milk is the ultimate nutrition for infant’s survival, growth and development. Also, EBF of infant for the first six months can reduce the morbidity and mortality of children especially in developing counties where poverty is high. In regions where HIV prevalence is on the increase, especially in sub- Saharan Africa, EBF has the potential of reducing the risk of mother-to-child transmission (MTCT) of HIV. According to World Health Organization (WHO), EBF levels are low in third world than the stated figure of 90% despite major resources being set aside for PMTCT counseling to increase the prevalence of EBF. However, in Kenya for example, the area with the most acknowledged comprehensive care clinics (CCCs) is the North Rift with approximately 35% prevalence of exclusive breastfeeding. The present study highlighted the predictors of exclusive breast feeding among HIV-positive mothers in Kenya. Methods: A descriptive cross-sectional study design was used on a sample of 297 HIV-positive mothers attending the five CCCs. The subjects were randomly selected proportionally in all the five health facilities. Socio-demographic, cultural and economic data was collected using a structured questionnaire. In addition, qualitative and quantitative data in form of Focus group discussions (FGDs) was conducted among the mothers who were selected purposively and the data analysed by summarizing and categorizing of verbalise response of participants and highlighting emerging themes. Also, the information generated was analysed using bivariate and multivariate regressions. Results: Prevalence of EBF was 63% confirming disparity with the recommended 90% prevalence. The main predictors of EBF were: OR (95% CI): education level 17.67 (0.906, 2.512); knowledge 17.85 (3.806, 8.372); stigma 0.19 (0.092, 0.394); traditional beliefs 0.03 (0.007, 0.154). Improving knowledge on breastfeeding can contribute to enhancing the prevalence of EBF in Kenya to achieve the WHO recommendation.