Technical Abstract: Aflatoxin contamination of agricultural commodities poses a potential risk to livestock and human health. It is not only a serious food safety concern, but it has also significant economic implications for the agricultural industry worldwide because of restrictions limiting the trade of contaminated crops. These concerns have lead to extensive studies on the occurrence, biosynthesis, and toxicity of aflatoxins. Over the last half century, intensive studies have been taken place on identification, characterization, toxicology, biosynthesis, genetics, and genetics regulation of aflatoxin biosythsis. In the last two decades, a major focus has been on understanding the genetic basis of aflatoxin biosynthesis. In the recent years, technological breakthroughs in large scale DNA sequencing has made it possible to study whole genome of Aspergillus flavus. Significant progress has been made in deciphering the aflatoxin biosynthetic pathway, genes involved in aflatoxin biosynthesis, and the A. flavus genome structure. In this chapter, we summarize the current progress on the genetics and genomics of A. flavus in an attempt to solve aflatoxin contamination of food and feed.