Summary: The solution of the nonlinear Troesch’s problem is obtained by means of homotopy perturbation method (HPM). Troesch’s problem arises in the investigation of the confinement of a plasma column by radiation pressure. The results reveal that the homotopy perturbation method (HPM) is very effective, convenient and quite accurate to nonlinear differential equations. It is predicted that the HPM can be found widely applicable in engineering.