Acetylene[14C2] is shown to be a useful starting material for the synthesis of a number of 14C‐labeled intermediates and small molecules. Its facile preparation from inexpensive barium carbonate[14C] and the range of transformations it undergoes allow the efficient syntheses of 2‐propyn‐[2,3‐14C2]‐1‐ol, 2‐propen[2,3‐14C2]‐1‐ol, 2‐propen[G‐14C]yl‐isothiocyanate, 2‐butanone[1,2‐14C2], furan[3,4‐14C2], p‐dioxane[U‐14C], and various other intermediates.