An acetal resin composition comprising:(A) 100 parts by weight of an acetal resin,(B) 0.01 to 5 parts by weight of a terminal-etherified polyalkylene glycol of the formula (I)R.sup.1 --O--(--R.sup.2 --O--).sub.m --R.sup.3wherein R.sup.1 is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 7 carbon atoms, an aryl group or an aralkyl group, R.sup.2 is an alkylene group having 2 to 3 carbon atoms, R.sup.3 is an aliphatic hydrocarbon group having 1 to 7 carbon atoms, an aryl group or an aralkyl group, and m is a number of at least 20, and(C) 0.01 to 2 parts by weight of an ester from a polyhydric alcohol having 2 to 10 carbon atoms and a higher fatty acid having 22 to 32 carbon atoms. This acetal resin composition has highly improved mold releasability when injection-molded without any substantial impairment of mechanicla properties and thermal stability inherent to an acetal resin and gives precision molded articles having little molding strain.