This work aimed to investigate the effects of graphene nanoparticles on the mechanical and morphological properties of gypsum plaster paste. In order to do so, samples of pure gypsum plaster paste with multilayer graphene were produced. These samples were prepared with a water/plaster factor (w/p) of approximately 0.5 with different graphene dosages. The mechanical analysis results showed that the graphene dosage of 0.02% increased the compressive and tensile strength values in the order of 120%. The increase in these properties is most likely due to the heat dissipation promoted by graphene, the greater production of crystalline nuclei and the reactivity of graphene with Ca2+ ions. Regarding the plaster setting times, a reduction in the values was observed for most samples, indicating an increase in the production of crystalline nuclei. FTIR analyzes indicate that there were no changes in terms of chemical properties.