The bi‐Maxwellian model is employed to study the time evolution of anisotropic distributions resulting from Coulomb collisions. The rate of change of temperatures caused by like‐particle collisions is described by a single ordinary differential equation for &Egr;, where &Egr;=T⊥/T∥. It exhibits a logarithmic singularity in the limit &Egr;→0, expressing the velocity space geometry and nonlinearity in the collision operator. The temporal relaxation is compared with a numerical solution of the nonlinear Fokker–Planck equation and is found to be insensitive to changes in the collision operator in the case of &Egr;>1. For &Egr;<1, however, the relaxation toward thermal equilibrium turns out to be dependent on the chosen model. The influence of unlike‐particle collisions is also investigated.