A novel vapor phase production process for CF 3 I was successfully developed for the reaction between CHF 3 with I 2 in the presence of a unique catalyst. The most effective catalyst system for this reaction was found to be alkali metal salts which were supported on an activated carbon carrier. A consideration of the reaction mechanism suggests that the reaction proceeds via CF 2 carbenes formed on the catalyst surface as intermediates, followed by carbene disproportionation to CF 3 radicals, followed by reaction with I 2 to give CF 3 I.