In a non-chiral environment, the enantiomers of a racemate possess the same physico-chemical properties but in the biological systems they possess different activities. One of the enantiomers may be more toxic or carcinogenic, and, therefore, the present data available on the toxicity and carcinogenesis of the racemic mixtures of these chiral pollutants are not reliable and need modification in terms of the enantioselective toxicity and carcinogenesis. It is essential to explore the enantioselective toxicity and carcinogenesis due to the different enantiomers of the chiral pollutants. The knowledge of the stereoselective metabolisms of the chiral pollutants may be useful for the treatment of cancer and other diseases. The enantioselective toxicity and carcinogenesis due to the chiral pesticides, pollutants and some drugs have been discussed in this review article.