The presented paper deals with the examination of the mold cavity filling process for the production of lightweight plastic profiles from material PE TIPELIN 7100S applying the technology of extrusion into the mold. The principle of the extrusion technology and the carrying out of the experiments are determined in the introductory parts. The following parts focus on the analysis and evaluation of the mold cavity filling process for the production of lightweight profiles from from material PE TIPELIN 7100S with orientation on the influence of the mold temperature on the mold cavity filling time and status.