CAP88-PC, Version 2.0, and NORMTRI, which are based on the Gaussian plume model, were used to estimate the chronic dose due to a continuous, ground-level, atmospheric release of tritium as tritiated water. For the same conditions the predictions of CAP88-PC were found to be higher by a factor of 3 or less than those of NORMTRI. The major differences are due to the use of higher dose coefficients in CAP88-PC and NORMTRI's method of calculating the tritium content of food.