[en] Two generic radiosynthetic routes for the preparation of [¹¹C-carbonyl]isocyanates have been developed. Reaction of N-organo-sulfinylamines; RNSO, (R=Me, Et, allyl, cyclohexyl and phenyl) with [¹¹C]phosgene gave the corresponding [¹¹C-carbonyl]isocyanates in good radiochemical yield (53-68%) from [¹¹C]phosgene (decay corrected) in ca 16 min from EOB. Alternatively, the reaction of [¹¹C]phosgene with N,N'-organo-ureas; (RNH)₂CO, (R=Me, Et, Pr and phenyl) also gave the corresponding [¹¹C-carbonyl]isocyanates in moderate radiochemical yield (9-37%) from [¹¹C]phosgene (decay corrected) in ca 16 min from EOB. For identification, the [¹¹C-carbonyl]organo-isocyanates were derivatized with 1-(2-methoxyphenyl)piperazine in situ to [¹¹C-carbonyl]carboxamides and the position of radiolabelling in the carbonyl group confirmed by [^11/13C]co-labeling and subsequent carbon-13 NMR spectroscopy