The (1) H, (13) C and (15) N spectra of aryl-substituted 1,3,4-thiadiazoles were recorded. The results obtained were correlated with Hammett coefficients. The experimental results were compared with DFT-calculated chemical shifts. The results obtained were compared with those for 1,3,4-oxadiazoles and 1,3,4-selenadiazoles.