Polymethy methacrylate (acrylic resin) has been the most commonly used denture base material since 1937, due to its excellent appearance, simple processing and easy repair. However, the mechanical strength of acrylic resin is inadequate to maintain the longevity of the denture. Fracture is one of the frequent problems that occur with acrylic denture bases. Over the years, several materials have been developed and introduced into the market in order to improve the acrylic resin mechanical properties and to reduce the denture fabrication time. The present study has been performed to determine the strength properties namely; transverse, impact and fatigue of some denture base materials. Three commercial types of acrylic denture base materials: rapid heat-cured, microwave-cured and a conventional were used. A total of 63 specimens were prepared for this study; 21 specimens for each material. Each material specimens were assigned according to the mode of the applied load; (n = 7) specimens were tested under static loading to determine the flexural strength; (n = 7) specimens were tested under sudden loading to calculate the impact strength and (n = 7) specimens were tested under cyclic loading to evaluate the fatigue strength. All the specimens were prepared in a brass molds with different dimensions according to each test specifications: The flexural strength test specimens were prepared with dimensions of (65102.5 mm), the impact strength test specimens were prepared with dimensions of (751010 mm) with central notch of 2 mm depth and tip angle of 45o and the fatigue strength test specimens were prepared with dimensions of (90 30 4 mm) with narrowest portion of 20 mm in diameter. The specimens of each tested materials were cured according to the manufacturer’s instructions: 1 1/2 h at 74°C and then for another 1 h at 100°C in water bath for the conventional heat–cured acrylic resin, 20 min at 100°C in water bath for the rapid heat-cured acrylic resin and finally, 3 min at power of 500 W in microwave oven for the microwave-cured acrylic resin. After finishing and polishing, the specimens were immersed in distilled water for 24 h before testing under 3-point bending test, Charpy impact test and plane fatigue test. Fourier Transform Infrared (FTIR) Spectrometer was used to determine the remaining double bonds of liquid, powder and their mixture before and after curing for the different investigated denture base resins. One-way ANOVA with Tukey’s post-hoc was used to compare the data. The result showed that the microwave-cured acrylic resin possessed the highest mean flexural strength value while there was no significant difference between the conventional and rapid heat-cured acrylic resins. On other hand, the microwave-cured acrylic resin showed the lowest impact strength value while there was no significant difference between the conventional and rapid heat-cured types. However, the fatigue strength values there were not significantly different among the investigated denture base materials. Finally, the microwave-cured acrylic resin revealed the highest degree of conversion while the conventional and rapid heat-cured types were not significantly different. Based on the results obtained from the present study the following conclusions could be drawn: 1. As being polymeric materials, the curing technique and consequently the degree of conversion (DC %) has the most prominent effect on the strength characteristics of the tested materials. 2. Microwave curing technique enhanced markedly the flexural strength of the microwave-cured acrylic resin. Meanwhile, it adversely affected its impact strength. 3. The different curing techniques used in this study had no effect on fatigue strength. 4. Microwave curing technique with its corresponding acrylic resin could be considered an acceptable substitution for the conventional heat-curing technique. 5. Conventional heat and rapid heat-curing techniques with their corresponding acrylic resins can be used alternatively as they have equivalent effects on flexural, impact, fatigue strength and DC%.