Theories are developed from two different assumptions to calculate the effect of irradiation growth on the creep of uranium under a uniaxial applied stress when the temperature is sufficiently high for the internal stresses set up by the differential expansions of the individual crystals to be insufficient of themselves to cause plastic flow. It is shown that the greater the irradiation growth the greater is the creep rate for a given stress; the effect on creep rate is also greater at lower applied stresses for a given irradiation growth.