Syntheses of [18F]haloperidol and [18F]spiroperidol in both no-carrier-added and carrier-added forms have been accomplished. The no-carrier-added [18F]butyrophenone neuroleptics were prepared in low (less than 2%) yield by acid decomposition of aryl piperidine triazenes. Carrier-added 18F-neuroleptics were prepared in better (5-17%) yields by 18F-for-19F nucleophilic aromatic substitution. The preparation of all synthetic precursors, and procedures for radiolabeling are fully described.