Polyurethane foams are made by curing a reaction mixture that contains an aromatic polyisocyanate, at least one isocyanate-reactive material having an average functionality of at least 2 and an equivalent weight of at least 200 per isocyanate-reactive group, at least one blowing agent, at least one surfactant and at least one catalyst, at least one cyclic 1, 3-diketone compound and optionally least one antioxidant. Foams so produced emit low levels of both formaldehyde and acetaldehyde.