An improved disinfecting and sterilizing composition having low odor and irritation potential is disclosed. The composition is an aqueous solution containing a 2 to 6 carbon atom dialdehyde and may also contain formaldehyde and a diol or monosubstituted diol of the formula RO(CH.sub.2 CH.sub.2 O).sub.n CH.sub.2 CH.sub.2 OH; where R is H or CH.sub.3 and n is an integer from 1 to about 22. Such compositions may be employed at a wide range of pH, from pH2 to pH9.