Background: Sleep is a state of reduced consciousness and responsiveness from which an individual can be aroused by external stimulus. Inhumans, is also associated with reduced movement. It enables to restore energy in the body and initiate neural plasticity for learning and memory.Several studies in the world identified poor sleep quality among nurses and tried to explore associated factors. But there is no any study inEthiopia on sleep quality and associated factors among nurses. Objectives: the main aim of this study was to determine the prevalence of sleepquality and associated factors among nurses in Jimma zone public hospitals. Methods: An institution based cross-sectional study was conductedon 550 nurses from June 1 to July 1, 2018. Data was collected using self-administered questionnaire; sleep quality was measured using PSQIwhich is standard validated tool. Collected data was checked for completeness, entered Epi data version 3.1 and exported to SPSS Version 20.0.Frequencies, means and percentages were used for the descriptive analysis of data. Bivariate analysis was done to select candidate variables.Variables having p< 0.05 was considered statistically significant. Results: A total of 528 nurses were included in the study with a response rateof 96%. The mean age was 31.73 7.36 years and 54.7% of nurses were females. Prevalence of poor sleep quality among nurses was 70.6%.According to the multiple logistic regression analysis current khat chewing, BMI in overweight individual, BMI in Obese individual, medium jobrelated stress, high job related stress , and Shift working were significantly associated with poor sleep quality. Conclusion: The magnitude of poorquality of sleep among nurses working in hospitals, Jimma Zone was very high. Independent predictors of poor sleep quality as identified by thisstudy were current khat chewing, overweight, obesity, job related stress, and shift work.