AbstractThe 1H, 13C, 15N, and 19F nuclear magnetic resonance (NMR) spectra of 11 2,5‐diaryl‐2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐ones have been acquired in DMSO‐d6 solution and the 13C, 15N, and 19F NMR spectra have also been acquired in the solid state (solid‐state nuclear magnetic resonance [SSNMR] and magic angle spinning [MAS]). The X‐ray structures of Compounds 3, 5, and 6 have been determined by X‐ray diffraction. Theoretical calculations at the gauge‐independent atomic orbital (GIAO)/B3LYP/6‐311++G(d,p) level have provided a set of 321 chemical shifts that were compared with 310 experimental values in DMSO‐d6. To obtain good agreements, some effects need to be included. The SSNMR chemical shifts have been compared with gauge‐including projector‐augmented wave (GIPAW) calculations and with the heavy atom–light atom (HALA) effects.