Background One of the key interventions to reduce unintended pregnancy and unsafe abortion outlined in the national youth strategy is availability of emergency contraception. However, there are no studies which document emergency contraception use and the factors influencing the use of emergency contraceptives among university girls in Ethiopia. This study was carried out to assess emergency contraception use and its predictor factors among regular female students at Adama University. Methods A cross-sectional study was conducted during the month of February 2009, among randomly selected 660 female students of Adama University Central Ethiopia. Data were collected through pre-tested selfadministered questionnaire. Bivariate and multivariable logistic regression models were fitted to identify variables predicting emergency contraception use. Results One hundred ninety four (29.4%) students were sexually active and 63 (9.4%) had a previous history of pregnancy. And most of the pregnancies (92%) were unintended. Majority (77.7%) of pregnancies were terminated by way of induced abortions carried out by untrained persons. Only 26.7% of those who had unprotected sex used emergency contraception. Lack of knowledge, fear of being seen by others, and inconvenient service delivery were pointed out as the main reasons for not using emergency contraceptives. Previous use of contraceptives (AOR: 1.953; 95% CI = 1.72- 6.345), being married (AOR: 9.254; 95% CI = 2.538-20.73) and age of 20 years and above (AOR: 2.372; 95% CI = 1.102-7.246) were significant predictors use of emergency contraception, while poor knowledge of emergency contraception was a significant predictor of non-use of emergency contraception (AOR: 0.09; 95% CI = 0.041-0.189). Conclusion The study pointed out the need for increasing the knowledge of university going young women about emergency contraception, and the need for availing youth friendly reproductive health services to promote preventive behavior.