Introduction:Mother to child transmission (MTCT) of HIV is the major source of HIV infection among children under the age of 15 years. Prevention of mother to child transmission (PMTCT) service has been an important strategy in preventing HIV infections in infants.However, improving PMTCT service uptake and continuum of care still remains a significant impediment in the Amhara Region of Ethiopia. The aim of this study was to explore factors that may hinder and promote PMTCT service utilization among HIV positive women.Methods: Phenomenological study design was used. Three focus group discussions (FGDs) with HIV positive women and five in-depth interviews with health care workers were conducted from the selected health institutions. Data analysis was conducted using thematic content analysis. ATLAS/ti version 7.5.16 software was used to assist in coding and analysis of the qualitative data. Results:The findings of the study revealed that there are a range of factors that influence HIV positive women on PMTCT service utilization. Stigma, discrimination, limited knowledge on HIV, lack of partner and family support, and not getting friendly service from health facility were factors that might hinder PMTCT service utilization. The experiences of HIV positive mothers revealed that continuous partner support, previous history of getting HIV free child, good health worker support, and advice by mother support group were factors that promote utilization of PMTCT service. Conclusions:Strengthening community awareness on HIV, engaging male involvement in PMTCT care and getting friendly service were the key determinants for the better PMTCT service utilization.