Denture wearers are strongly urged to practice regular oral and denture hygiene to maintain good oral and general health. Denture cleansing by chemical agents is an easily practiced method that requires simply the immersion of the denture in a commercially available solution according to the manufacturer's instructions. In selecting a disinfectant for dental prosthesis, compatibility between the disinfectant and the type of denture base material must be considered to avoid adverse effects in it. The aim of this study is to evaluate the effect of over the counter denture cleansers on the transvers strength of three denture base materials. Heat cure acrylic rein, self cure acrylic rein and the Thermoplastic groups specimens were immersed for one week (5 hours per a day) in peroxide effervescent denture cleansers (Corega Tabs, & Fittydent) and finally 2% Chlorhexidine. Distilled water was used as the control group. Transvers strength was measured using three-point bending test in a universal testing machine. Data were analyzed with ANOVA and Post-hoc Tukey's tests. The results showed multi variance analysis revealed high significance p ≤ 0.005 for solutions and resin types, and the interaction of these factors on transverse strength. Conclusion: transverse strength of denture base material can be altered by the disinfectant solutions tested as well as by the type of resin.