Small specimens (4 mm gage length, 1.3 mm diameter) of AISI 20% coldworked (CW) 316 stainless steel have been irradiated at 700°C up to 2 × 10²² n/cm². Ageing at 650°C as well as irradiation caused a reduction in creep life and an increase in minimum creep rate as compared with as-received specimens. An investigation of a possible size effect indicated no difference between creep results obtained on these small specimens and on larger ones.