rac-Benzyl 3-oxohexa-hydro-1H-pyrrolo[3,4-c]pyridine-5(6H)-carboxyl-ate was separated by chiral chromatography, and one of the enanti-omers ([α](22) (D) = +10°) was hydrogenated in the presence of Pd/C in methanol, producing octa-hydro-3H-pyrrolo[3,4-c]pyridin-3-one. The latter was reacted with (2R)-3,3,3-trifluoro-2-meth-oxy-2-phenyl-propanoyl chloride [(R)-(-)-Mosher acid chloride], giving rise to the title compound, C(17)H(19)F(3)N(2)O(3)·H(2)O. The present structure established the absolute configuration of the pyrrolopiperidine fragment based on the known configuration of the (R)-Mosher acid chloride. The piperidine ring has a somewhat distorted chair conformation and is cis-fused with the five-membered envelope-shaped ring; the plane of the exocyclic amide bond is approximately orthogonal to the plane of the phenyl ring, making a dihedral angle of 82.31 (3)°. The water mol-ecule acts as an acceptor to the proton of the amino group in an N-H⋯O inter-action, and as a double proton donor in O-H⋯O hydrogen bonds, generating infinite bands along the a axis.