BACKGROUND:Globally, 370,000 children became newly infected with HIV and an estimated 42,000-60,000 pregnant woman died because of HIV annually. Pediatric HIV infection in 90% of the cases was acquired from their mothers. METHODS: Comparative cross-sectional study design was implemented. Epi-info software was used to calculate the sample size, and the estimated sample size was 2667 pregnant women. Data were collected using exit interview technique. Descriptive statistical techniques were used to identify the prevalence of PMTCT service utilization and binary logistic regression was used to identify the determinants of PMTCT service utilization. RESULTS: A total of 2615 respondents were included for a response rate of 98.05%. Only 61.3% of the pregnant women attending ANC in the health facility were utilizing PMTCT services [95% CI: 59 %-63 %]. Around 3.22% of tested pregnant women did not receive their result. PMTCT service utilization was affected by knowledge of PMTCT [AOR 1.87, 95 % CI: 1.53-2.28], residence [AOR 0.67, 95 % CI: 0.51-0.89], internal referral system [AOR 3.06, 95% CI: 2.51-3.72], health professional client interaction [AOR 2.18, 95% CI: 1.75-2.76], fear [AOR 1.23, 95% CI: 1.03-1.47], long waiting time [AOR 0.74, 95% CI: 0.58-0.94], number of ANC visit [AOR 1.79, 95% CI: 1.4-2.29], gravidity [AOR 0.55, 95% CI: 0.46-0.66], educational status [AOR 1.43, 95% CI: 1.04-1.96] and involvement in PMTCT services [AOR 2.57, 95% CI: 1.51-4.4].  CONCLUSION: PMTCT service utilization was low in the study area. The presence of internal referral system significantly increases PMTCT service utilization.KEYWORDS: PMTCT, Service, Utilization, Determinants, Amhara Region