A crystal plasticity finite element model has been developed to study the effect of friction between the die wall and the billet on texture evolution during equal channel angular pressing of an aluminum single crystal. Four cases with different coefficients of friction mu = 0, 0.05, 0.1, and 0.15 have been simulated. It has been found that the friction of mu = 0.05 and 0.1 can capture the major texture features shown in the experimental results, and mu = 0.05 predicts a slightly better texture than mu = 0.1. The frictional condition significantly affects texture evolution in the region between 1/2 and 3/4 of the billet thickness from the top surface. It can be attributed to the effect of friction on the corner gap and the distribution of stresses in the die corner.