Human immunodeficiency virus (HIV) positive women report confusion about the best feeding methods. Exclusive Breastfeeding (EBF) practices in HIV-positive mothers are sub-optimal in Ethiopia. This study aimed to identify the main factors influencing EBF among HIV-positive breastfeeding mothers. A facility-based cross-sectional study was carried out from September 01, 2017, to June 30, 2018, among HIV-positive mothers with infants aged 6-23 months. Thirteen public health facilities (seven health centres and six hospitals) that provided anti-retroviral treatment (ART) and Prevention of mother-to-child transmission (PMTCT) services, found in three districts of Oromia, were randomly selected. Respondents were recruited by systematic random sampling techniques from these facilities using client registers as a sampling frame. EBF is an outcome variable. Data were collected using face-to-face interviews with a pre-tested questionnaire and analysed using SPSS Version 20 for windows. Associations were declared at P