In recent years, the steroidal glycoalkaloids have emerged as an important class of bioactive compounds. Their occurrence in a number of foods and their diverse biological activities has encouraged the development of more efficient procedures for their isolation, purification and analysis, and more sensitive methods of detection and structure determination. This review is mainly concerned with new approaches for the characterization of these metabolites. The formation of artifacts of isolation and purification is discussed. The limited information on their biosynthesis is summarized.