Through knowledge of the chemical and mechanical properties of acrylic substances used for removable prostheses is of a great practical importance in the technology of their production. The resistance of acrylic resins to mechanical forces varies significantly depending on their composition and the polymerization technology used in their pro-duction. Several heat-curing acrylic resins have been tested to establish the dependence of their flexural strengths on the technology of polymerization used in their production. The tests were performed using a S.A.D.A.M.E.L., TYP MG-EMC apparatus. The test samples had been produced using three different polymerization processes: the short, medium duration and long process. A total of 268 acrylic resin samples (Paladon 65, Superacryl special and Biocryl-R) have been tested. The highest flexural strength values for Paladon 65 (171.48") were obtained with samples produced by the longest poly¬merization procedure. The flexural strengths of Superacryl Special samples obtained by medium duration and long polymerization were very similar (171.88° and 171.91°, respectively). No statistically significant differences could be demonstrated among the fletural strengths of Biocryl-R samples produced by short, medium duration and long polymerization (171.56°, 172.02° and 171.53°, respectively), which finding indicates that this material is the least dependent on the duration of the polymerization process.