Organic agriculture is being promoted in Iran to address environmental problems resulting from the use of chemical materials in agriculture. Despite many advantages of organic agriculture, the results of several case studies show that its adoption rate is still very low among farmers. The purpose of this paper is to review previous studies that investigated the main factors influencing and challenging the adoption of organic agriculture. The review included journal articles and conference papers from 2007 to 2012. The results show that Iranian farmers have strong motives for the adoption, yet face challenges in certifying, marketing, and accessing reliable technical information and credits. Given the review of factors that govern farmers' adoption of organic agriculture, key mechanisms for promoting farmers' adoption are discussed. Further research is needed to learn how to bring these mechanisms into play in Iran.