7-Fluoro-4-(4-fluorophenyl)-2-[4-(4-fluorophenyl)-4-hydroxybutyl]-1,2,3,4-tetrahydropyrrolo[3,4-b]indole displayed neuroleptic-like activity in an animal model approximately equipotent with that of chlorpromazine but was of substantially greater duration of action. Structure-activity relationships of the series are discussed.