The crystal structure of the title compound {systematic name: (S)-(+)-N-[1-(2-chloro-phen-yl)-2-oxocyclo-hexyl]meth-anam-in-ium chloride}, C(13)H(17)ClNO(+)·Cl(-), was determined at 90 (2) K. The (S)-(+)-ketamine hydro-chloride salt is a well known anesthetic compound and is dramatically more potent than its R isomer. In the title compound, the cyclo-hexa-none ring adopts a chair conformation with the oxo group in the equatorial orientation. The methyl-amino and 2-chloro-phenyl groups at the 2-position have an equatorial and an axial orientation, respectively. The packing of ions is stabilized by an infinite one-dimensional ⋯Cl⋯H-N-H⋯Cl⋯ hydrogen-bonding network, involving NH(2) (+) groups as donors and chloride anions as acceptors.