AbstractPropargylation of 3‐substituted‐1,2,4‐triazole‐5‐thiols, which predominantly exist as their thione tautomers, was carried out with the view to synthesize different heterocycles and study their biological activity. Three different products namely, a mono S‐propargyl and two S,N‐dipropargyl regioisomers, arising from N1/N2 substitution, were isolated and characterized. Unambiguous structural elucidation of the regioisomers of S,N‐dipropargyl derivatives was achieved by means of 13C1H HMBC technique. The proportion of the regioisomers was found to vary with the substituent on the 1,2,4‐triazole thiols. No product corresponding to N4 substitution was isolated from any of the reactions carried out. Copyright © 2008 John Wiley & Sons, Ltd.