The invention concerns polyester resins, more particularly polyethyleneterephthalate resins used for making hollow containers, such as bottles for packaging liquid substances, in particular aerated beverages, natural or mineral waters. The invention concerns a polyester comprising at least 92.5% in number of recurrent units derived from terephthalic acid of aliphatic diols having an intrinsic viscosity ranging between 0.45 dl/g and 0.70 dl/g, and an acetaldehyde content less than 3 ppm, preferably less than 1.5 ppm. The invention also concerns a method for obtaining polyester granules with low acetaldehyde content having an intrinsic viscosity in the range mentioned above. Said polyesters are used in particular for making hollow containers such as bottles and more particularly bottles designed to contain foodstuffs sensitive to acetaldehyde.