The 573 K low-cycle fatigue behavior of Zircaloy-2 in various metallurgical states has been studied. Reduction in area as measured in tension tests was found to be a good parameter in determining fatigue life. Holdtimes in tension of 1 h or less did not affect the fatigue life but one of 5 h reduced it. An atmosphere containing iodine reduces the fatigue life under the conditions tested by 40 percent.