This study aims at identifying factors which affect the adoption of improved maize varieties in three woredas in Central Oromia, Ethiopia. The study utilized cross-sectional farm household level data collected by CIMMYT from 300 randomly selected sample households in 2012/13. Both descriptive and econometric methods have been used to analyze the data. The descriptive statistics were utilized to compare adopters and non-adopters. The logit model was employed to assess the adoption determinants.The descriptive analyses results show the existence of significant mean and proportion difference between adopters and non-adopters in terms of farmer characteristics. Adoption of the improved maize varieties among households was found to be positively influenced by adult-literacy, family size, livestock wealth, access to output market and credit access for the new varieties. On the other hand, farmer associations, distance to main markets and fertilizer credit negatively influenced adoption. Thus, the finding of this study revealed that educating farmers, strengthening extension services, improving farmer associations and improving market opportunities are some of the measures that need to be taken to enhance adoption of improved maize varieties by farmers.