Chirality as an environmental phenomenon was dealt with in a thorough and interesting manner in a series of three symposia entitled "Modern Chiral Pesticides: Enantioselectivity and Its Consequences", sponsored by the Agrochemical Division of the American Chemical Society and held in Washington, DC (2005), Boston, MA (2007) and San Francisco, CA (2010). All three symposia included speakers from industry, government and academia, representing several European countries, China, and the United States. Corresponding to this broad group of countries, institutions and speakers, the range of topics touched on almost all facets of chirality as it is manifested in environmental and human exposure and toxicity. The 40 oral and 20 poster presentations indeed approached comprehensive coverage: analysis of enantiomers and other stereoisomers; preparative separation of enantiomers; stereoselective occurrences of chiral pesticides in environment soil and water and in wildlife and human tissues and fluids; stereoselective degradation and metabolism of chiral pesticides; and stereoselective toxicity. This book is a result of manuscript contributions by some of the oral and poster presenters to the third symposium in 2010. In addition to symposium participants, invitations were extended to the environmental chiral chemistry community in general, including most of the speakers in the 2005 and 2007 symposia, in an attempt to attain good coverage of this rather broad topic. Thus, this ACS Symposium book will generate many new ideas from interested readers and inform them of useful techniques for experimental exploration of the somewhat exotic, but important, area of chiral chemistry of pesticides.