Details are reported for the preparation of the 2-aminoethyl, 3-aminopropyl sulfide from 3-bromopropylamine and 2-mercaptoethylamine. For this compound, the shorter name cystathionamine is proposed. The corresponding sulfoxide and sulfone have been also prepared. Some analytical data and chromatographic properties are reported. Preliminary results show that cystathionamine is a good substrate for the pig kidney diamineoxidase.