The continuing growth of the world population has become an urgent global problem. Ethiopia like most countries in Sub-Saharan Africa is experiencing rapid population growth. Currently, the country’s population is growing at a rate of 2.6% per annum, and if it continues unabated, the population will have doubled in 26 years. According to the last three Ethiopian Demographic and Health Surveys (EDHS) of 2000, 2005 and 2011 the contraceptive use trend in Harari region is low when compared to national target of 66%, with only 19%, 29% and 32% of married women using a modern contraceptive method respectively. Hence, assessing and understanding why women of child bearing age do not use family planning is critical to address unmet needs and to increase contraceptive use. Objective: is to assess the prevalence and associated factors influencing the utilization of modern contraception among women in the reproductive age group in Harari Region. Methods: A community- based cross-sectional study with internal comparison were conducted from December 2013 to January, 2014 among 1544 reproductive age women. Multi-stage sampling techniques were used. Data was entered in to Epi-data and were analy