Abstract:Background: Obstructed labor is one of the common preventable causes of maternal and perinatal morbidity and mortality in developing countries. In the last decade among the top four causes of maternal mortality, obstructed labor /uterine rupture accounted for 36% of maternal mortality in Ethiopia. The aim of this study was to determine magnitude of obstructed labor and its associated risk factors among mothers come for delivery services in Adama Hospital Medical College from June 01 to July 30, 2015. Methods: Hospital-based cross-sectional study was employed. Descriptive statistics was used to summarize socio-demographic variables and characteristics of delivery. Using binary logistic regression analysis, Odds ratio and confidence interval were used to determine statistically associated risk factors with obstructed labor. Result: Of 384 deliveries during the study period 9.6% were obstructed labor cases. The causes of obstructed labor identified by clinician on mother medical record were CPD (54.1%), mal-position (29.7%) and mal-presentation 16.2%). The independent predictors of obstructed labor using logistic regression analysis were duration of labor before arrival to the health facility greater than 24 hour (OR: 6.2; 95%CI: 2.7, 14.2), 4 to 6 hours of travel to health facility (OR: 2.9; 95%CI: 1.1, 10.6), malpresentation (OR: 6; 95%CI: 1.7, 12.8) and fetal weight greater than 4 Kilo gram (OR: 11.2; 95%CI: 2.4, 13.2). Conclusion: magnitude of OL is comparatively higher, especially among mothers of low educational status. Socio-demographic and health system factors increase the risk of obstructed labor. As most of the risk factors associated with obstructed labor need long term exposure for the outcome to be seen, prevention need inter sectoral collaboration from education, agriculture, health and other social sectors.