Objectives: The aim of this paper was to analysis the effects of disinfectant solutions on polyoxymethylene viscoelastic properties in comparison with polymethyl methacrylate. Materials and Methods: Polymethyl methacrylate and polyoxymethylene acrylic and 200 mL 5% chlorhexidine gluconate, 2% sodium hypochlorite and one Corega Tabs dissolved in 200 mL water at 40°C were used. The storage modulus, loss modulus, Tand and glass transition temperatures of the disinfected acrylic resins were observed with the Thermal Dynamic Mechanical Analyzer. Results: Lower storage modulus values were observed in the disinfectant solutions at polymethyl methacrylate specimens. The storage modulus showed lower values than the control group at chlorhexidine gluconate, higher values at sodium hypochlorite in the disinfectant solutions at polyoxymethylene specimens. While the glass transition temperatures of polymethyl methacrylate in the disinfectant solutions showed proximal values, the glass transition temperatures of polyoxymethylene in the chlorhexidine gluconate showed lower temperatures (approximately 11%). Conclusions: The storage modulus, loss modulus, Tand values of polyoxymethylene were lower than those of Polymethyl methacrylate. The Corega Tabs did not affect the viscoelastic properties of polyoxymethylene. Chlorhexidine gluconate and sodium hypochlorite did not affect the viscoelastic properties of polymethyl methacrylate.