Dedicated to Professor Richard A. Bartsch on the occasion of his 70th birthday AbstractOptically active aziridines were synthesized from the reaction of chiral nonracemic N-tertbutanesulfinyl imines with benzyl-stabilized sulfur ylides, wherein the latter were generated from a rhodium-catalyzed decomposition of phenyldiazomethane (PDM) in the presence of various sulfides. In most cases, the aziridines were formed and isolated in quantitative yield and the 2,3-trans-aziridines were found to predominate over the 2,3-cis-aziridine isomers. The diastereoselectivity between the two trans-aziridines was found to vary significantly, depending upon the solvent and sulfide employed in the reaction.