The aim of this in vitro study was to compare the impact strength of three kinds of heat polymerised acrylic resin: a microwave polymerised acrylic resin, a visible light cured resin and a self-cured acrylic resin. From a group of six different materials, a total of 60 specimens (75 x 10 x 3 mm) were fabricated, 10 from each material. The impact strength was evaluated using the Charpy method. The test was performed at room temperature in an impact testing machine (Zwick pendulum impact tester; Zwick GmbH & Co. KG, Ulm, Germany) of a capacity of 0-7.5 J scale; the specimens were fractured. For statistical analysis, Kruskal-Wallis test followed by Dunn's multiple comparison test was used. The impact strength values exhibited statistically significant differences among acrylic resin groups (p=0.0001). High impact strength acrylic resin showed the highest mean impact strength value among the materials tested.