It has been discovered that aminocarboxylic acids are effective breakers for polymer-gelled aqueous fracturing fluids, particularly in the temperature range between about 120.degree. F. (49.degree. C.) and about 280.degree. F. (138.degree. C.). The aminocarboxylic acids are believed to act directly on the polymer and not to any great extent or not to as an effective extent on a crosslinking agent, if present. The polymer may be a polysaccharide, and the aminocarboxylic acid may be selected from the group including, but not necessarily limited to, tetrasodium ethylenediaminetetraacetic acid (Na.sub.4EDTA), tetrasodium propylenediaminetetraacetic acid (Na.sub.4PDTA), trisodium hydroxyethylenediaminetetraacetic acid (Na.sub.4HEDTA), trisodium nitrilotriacetic acid (Na.sub.3NTA), salts of these acids, and mixtures thereof.