This study was carried out in Shashemene district of Ethiopia to evaluate factors affecting adoption decision and use intensity of organic fertilizer as well as its effect on farm income amongst smallholder farmers. The study used primary data which was collected from 368 farmers. Propensity score matching and Cragg's double hurdle model were used to analyze the data. The results of the study would help farmers, policy makers, and other development practitioners targeted at improving farm productivity through adoption of organic fertilizer.