A study on the SN2-type ringopeningreactions of aziridines with indoles as nucleophiles is reported. Under gold(I) catalysis a great variety of tryptamine derivatives were prepared in good to excellent yields with complete stereocontrol when chiral aziridines were used. We demonstrated that cationic gold(I) catalysts are superior Lewis acids to the previously reported group 3, 12 and 13 metals in