Tetrahydrothiopyrano[3,2-b]indole derivatives represented by the formula I: ##STR1## wherein R.sup.1 is hydrogen, C.sub.1-4 alkyl, C.sub.2-4 alkenyl, C.sub.2-4 alkynyl, phenyl-C.sub.1-4 alkyl, C.sub.2-5 alkanoyl, or ##STR2## wherein Y is C.sub.1-4 alkylene or C.sub.1-4 oxoalkylene and R.sup.5 and R.sup.6 each is hydrogen or C.sub.1-4 alkyl; R.sup.2 is hydrogen, C.sub.1-4 alkyl or C.sub.3-6 cycloalkyl; R.sup.3 is hydrogen, C.sub.1-4 alkyl or ##STR3## wherein Y, R.sup.5 and R.sup.6 each is as defined above; or ##STR4## is pyrrolidino, piperdinyl, piperazinyl, 4-C.sub.1-4 alkylpiperazinyl or morpholino; R.sup.4 is hydrogen or C.sub.1-4 alkyl; and n is 0 or an integer of 1 or 2 and the pharmaceutically acceptable salts being useful as analgesic and anti-inflammatory agents as well as psychoanaleptic and nootropic drug.