It is argued that the existence of the new compounds of glycine recently reported by M.M. Khandpekar and S.P. Pati (2Gly center dot HF center dot HCl (J. Cryst. Growth 312 (2010) 1150-1153), 2Gly center dot H(2)SO(4) center dot HNO(3) (Opt. Commun. 283 (2010) 2700-2704), 3Gly center dot KIO(3) (Solid State Sci. 12 (2010) 1831-1836), 3Gly center dot KNO(3) (Opt. Commun. 284 (2011) 818-823)) is dubious. We present data indicating that these compounds are not what the authors propose and want to use these examples to express the necessity of a sound single crystal analysis for the characterization of novel compounds (C) 2011 Elsevier B.V. All rights reserved.