Introduction: Perinatal mortality is the death of a baby between 28 weeks of gestation onwards and before the first 7 days of life. According to WHO, Ethiopia is one of the most commonly noticed country in the world in considering perinatal mortality rate. The overall perinatal mortality rate in Ethiopia was around 66–124 per 1,000 births. Objective: To determine the magnitude of perinatal mortality and associated factors among mothers who attended antenatal care at public hospitals in Gamo Zone, Southern Ethiopia. Methods: A cross-sectional study was conducted at Arba Minch General Hospital and Chencha District Hospital antenatal care attended by pregnant mothers from the 1st of February to the 28th of March 2019, among the mothers enrolled at ANC clinic from the 1st of January to the 30th of December 2018 using a simple random sampling method for the pre-determined 1,820 records. Both bivariate and multivariable logistic regression analysis was conducted. Variables which had a p-value <0.25 in bivariate analysis were considered as a candidate variable for multivariable analysis and variables which had a P-value <0.05 in multivariable analysis were declared as statically significant. Results: The prevalence of perinatal mortality was 12.6% (95% CI: 11.80, 13.40) and grand multiparity (AOR: 7.40; 95% CI: 2.77, 20.26), having one antenatal visit (AOR: 4.40; 95% CI: 1.64, 11.91), spontaneous vaginal delivery (AOR: 0.36; 95% CI: 0.16, 0.82), being pre-term (AOR: 6.78; 95% CI: 2.41, 19.09), birth weight <2,500 gram (AOR: 3.10; 95% CI: 1.48, 6.46), maternal ever hemoglobin level <10 gm/dl (AOR: 4.04; 95% CI: 1.91, 8.57), and pre-partum onset of pregnancy induced hypertension (AOR: 4.01; 95% CI: 2.01, 6.08) were statistically significant in the multivariable logistic regression model. Conclusion: The magnitude of perinatal mortality was high as compared with the Ethiopian Health and Demographic Survey report 2016 and high parity, low in number of antenatal care visits, low gestational age, low birth weight, low maternal hemoglobin level, and pre-partum onset of pregnancy induced hypertension were independent factors which increase the perinatal mortality while spontaneous vaginal delivery reduces the mortality risk. Therefore; the community should be educated to reduce the number of instance of births. In addition; the health care professionals should emphasize on the care provided for the newborns having low birth weight and use spontaneous vaginal delivery as much as possible.
