Stereo- and regioselective biotransformations is an area of intense research interest. The ability to take advantage of microorganisms and isolated enzyme systems to perform selective organic syntheses is well known. In recent years, several new methodologies have caused a rapid growth in the area of selective biotransformations. These novel techniques include genetic and protein engineering, biocatalysis in organic media, improved screening procedures, as well as an increased awareness of the value of biotechnology to solve important problems in organic synthesis. Recent US patents and scientific literature on stereo- and regioselective biotransformations are surveyed. Patent abstracts are summarized individually and a list of literature references are given.