The manufacture of plastic components typically involves large deformations of the material, interaction with rigid boundaries, and a material constitutive response which depends strongly on temperature and the rate of straining. In service, material response may change with time, and a component may undergo large deformations under load. Numerical analysis of manufacturing processes and of plastic components under load must account for these nonlinear effects. The paper discusses nonlinear finite element analysis in the context of plastics manufacturing and in-service loading of plastic components. Some currently available techniques are illustrated with an example of creep induced buckling, an example of warping due to post-forming cooling, and a case involving blow molding.