Background Partographs should be used universally to monitor the mother and fetus’s conditions during delivery. However, its application in different parts of the world, including Ethiopia, is inconsistent. Moreover, its magnitude has not been determined in study area. As a result, the aim of this study was to investigate the utilization of partograph and associated factors among obstetric caregivers in public health institutions of Southwest Ethiopian. Methods An institutional-based cross-sectional study was conducted in Southwest Ethiopia from March 1st to June 30th, 2018. A simple random sampling technique was used to select study participants. A self-administered questionnaire was used to gather data on background characteristics, knowledge of partograph, and partograph utilization. The collected data were entered into an EPI Info and analysed using SPSS Version 22. We used bivariate and multivariate logistic regression analysis. Frequencies, tables, and graphs were used to present the final results. To determine statistical significance, a P-value of less than 0.05 was used. Result The response rate of this study was 393(92.2 %). The magnitude of utilization of partograph was 43 % with (95 % CI: 38.4, 48.1). According to the multivariate analysis being nurse or health officer [AOR = 0.37(0.21, 0.66)], degree level educational qualification [AOR = 0.32 (0.17, 0.60)], being trainined on partograph [Adjusted OR = 7.83 (95 % CI: (4.54, 13.50)], good knowledge about partograph [AOR = 5.84 (95 % CI: (3.27, 10.44)] and working at health center [AOR = 1.99 (95 % CI: (1.12, 3.52)] were found as determinants of partograph utilization. Conclusions The magnitude of partograph utilization among obstetric caregivers was found to be low in this study. Partograph utilization was determined by the type of profession, qualification level, knowledge of partograph, in-service training, and type of institution. To ensure its regular, obstetric caregivers must receive training and gain knowledge about it.