A numerical solution of the Boltzmann equation with the Bhatnagar‐Gross‐Krook model is obtained for Poiseuille flow and thermal creep of a rarefied gas between two parallel plates. The numerical results of Poiseuille flow are in fair agreement wth the experimental data of Dong and predict the Knudsen minimum in volume flow rate. The present results of the thermal creep approach a thermal transpiration formula analyzed on the basis of the elementary kinetic theory of gases as the density of the gas decreases and agree well with Maxwell's equation continuum theory in the range of low Knudsen number. The effect of the thermal creep on the velocity profile of Poiseuille flow is very large, especially at the Knudsen layer near the plate.