Positive photoresist compositions comprising, in an organic solvent, at leasta) one alkali-soluble resin,b) one photosensitive quinone diazide,c) one aromatic hydroxy compound of formula I ##STR1## wherein each R is --H, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, --OCH.sub.2 C.sub.6 H.sub.5, --OC.sub.6 H.sub.5 or --COOC.sub.1 -C.sub.4 alkyl, and R.sub.1 and R.sub.2 are each independently of the other H, C.sub.1 -C.sub.4 alkyl, --C.sub.6 H.sub.5 or a cycloaliphatic 5- or 6-membered ring, a is an integer from 0 to 4, and m and n are each independently of the other 0, 1 or 2, which compound enhances the photosensitivity and/or the rate of development, and optionallyd) additional customary modifiers, are eminently suitable for making relief structures.