Abstract: The series of the interaction products of substituted benzaldehydes XC₆H₄CHO with several aliphatic diols (ethanediol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, and racemic 2,3-butanediol) were characterized for the first time by analytical parameters required for their chromatography–mass spectrometric identification: electron ionization mass spectra and gas-chromatographic retention indices (RIs) on a standard nonpolar polydimethylsiloxane stationary phase. It was found that it is expedient to combine this characterization of new compounds with controlling the correctness of the RIs by checking their correlations with data for one or several series of simpler and, therefore, characterized in more detail structural analogs. The proposed algorithm made it possible not only to confirm the correctness of all of the newly determined retention indices but also to reveal an erroneous reference value of the retention index of 4-ethoxyphenol. An appropriate selection of structural analogs provides an opportunity to use this method for controlling the retention indices of compounds in whose molecules steric interactions of structural fragments are manifested.