The postirradiation fatigue-crack propagation behavior of solution-annealed Type-304 and 20% cold-worked Type-316 stainless steels irradiated to a fluence of 1.3 × 1021 n/cm2 (E >0.1 MeV) at temperatures of ∼851 and 891°F (455 and 477°C) was characterized using linear elastic fracture mechanics techniques. Irradiation to this fluence had little or no effect on the crack growth behavior of both materials at test temperatures of 800 and 1000°F (427 and 538°C).