We present new simulations of the domain-growth kinetics for the Q-state Potts model in two and three dimensions. The time dependence of the average grain radius R-bar can be described by R-barapprox. =Bt/sup n/, where B is a temperature-dependent constant. In two dimensions, we find n = 0.49 +- 0.02 for a range of Q values from 2 to 48. This value of n is obtained from very long simulations on lattices up to size 1000/sup 2/ and is in contrast to our earlier estimates for n which were less than (1/2 (napprox. =0.41 +- 0.01) for large Q. In three dimensions on lattices of size 100/sup 3/, we find that n = 0.48 +- 0.04 if early-time data are excluded from the fit to the kinetic data but smaller if the entire data set is used. The grain-size distribution for several values of Q in both two and three dimensions is also determined and compared with our results for grain growth in real polycrystalline materials.