The main purpose of this study was to assess the practices and challenges of school principals in time management in government secondary schools of East Wollega Zone, Oromia National Regional State. The design selected for the study was mixed both quantitative and qualitative methods were employed to analyze data. The study was carried out in seventeen government secondary schools of East wollega Zone which was selected by comprehensive sampling technique. A total of 219 participants which included teachers, department heads, vice principals, principals and supervisors were involved in the study. Questionnaire, interview, FGD, and document analysis were the instruments of data collection. The data collected were analyzed using frequency, mean and standard deviation and summaries of views. The outcomes of the study suggested that principals face low practice in their time management those were lack of managing meetings, failure to delegate, and interruptions by visitors. The study also identified the major challenges of principals' in time management were lack of training in educational leadership, ,lack of enough experience in leading the schools, and allocate more time for School Vision Leadership, Administrative Leadership and allocate less time for Instructional Leadership respectively. As a result, the recommendations forwarded were: principals should improve their practices and implementing time management strategies effectively to minimize challenges that waste their time and allocate more time to instructional tasks. It is advisable if East Wollega Education Office and Woreda Educational office should be arranged workshops for inservic principals to equip them with skills, knowledge and attitue to improve time management skills In addition make the principals obey their responsibility to lead the school rather take part in kebele administration tasks.