A hair cosmetic composition comprising a cosmetic base containing 0.5 to 40% by weight of a diol derivative having the formula (I): ##STR1## wherein X.sub.1 is R--or ##STR2## in which R is branched alkyl having 6 to 12 carbon atoms, X.sub.2 is --H or ##STR3## in which R is branched alkyl having 6 to 12 carbon atoms, R.sub.1 is H, CH.sub.3, C.sub.2 H.sub.5 or C.sub.3 H.sub.7, R.sub.2 is H, CH.sub.3, C.sub.2 H.sub.5 or OH, and n and m each is an integer of from 1 to 3,or a branched aliphatic alcohol having the formula (II): ##STR4## wherein R.sub.3 is linear or branched alkyl having 8 to 10 carbon atoms and R.sub.4 is linear or branched alkyl having 6 to 8 carbon atoms,said hair cosmetic composition also having incorporated therein from 0.5 to 10% of a methylpolysiloxane having the formula (III): ##STR5## wherein l is an integer of from 3 to 14.