Type 304 stainless steel has been irradiated to a fluence of 1.4 × 1027 n/m2, E > 0.1 MeV, in the solution-annealed and 10, 20, and 30% cold-worked conditions. Cold working does not impart a continuous reduction in swelling for this alloy. Indeed, in the temperature range from 475 to 550°C (748 to 823 K), the 10 and 20% cold-worked specimens showed more swelling than the alloy in the solution-annealed condition. This behavior appears to be a consequence of differing temperature dependences of swelling. Peak swelling in the cold-worked materials occurs somewhere between 475 and 550°C (748 and 823 K), while the solution-annealed condition peaks at a lower temperature.