The asymmetric unit (C17H25N3O5.C3H8O.2H2O) consists of two crystallographically independent peptide molecules, A and B, with different conformations, chi 1(2) being trans and gauche- for the Leu residues in molecules A and B, respectively. The backbone conformation of both peptide molecules resembles that of the beta-pleated sheet arrangement found in proteins. Comparison with two other structures containing the tripeptide Gly-L-Leu-L-Tyr reveals almost identical molecular conformations, and in one instance also a common packing pattern.