An analgetic composition which comprises, as an active ingredient, a therapeutically effective amount of a synergistic mixture of an indole-3-acetic acid derivative of the formula, ##STR1## wherein R is a halobenzoyl, piperonylcyl or cinnamoyl group and R.sub.1 is a 5-methoxy or 5,6-methylenedioxy group; and a narcotic or anti-narcotic analgesic selected from the group consisting of a compound of the formula, ##STR2## wherein R.sub.2 and R.sub.3 are each a C.sub.1 - C.sub.3 alkyl group and R.sub.4 is a 4-(4-fluorophenyl)-4-oxobutyl, cyclopropylmethyl or 3-methyl-2-butenyl group; a compound of the formula, ##STR3## wherein R.sub.5 is a hydrogen atom or a C.sub.1 - C.sub.3 alkyl group; a compound of the formula, ##STR4## and a compound of the formula, ##STR5## wherein R.sub.6 is a C.sub.1 - C.sub.3 alkyl group; and a pharmaceutically acceptable carrier or diluent and its preparation and a method of obtaining analgesia which comprises administering the same to a patient.