The influence of the particle size of an ash from sugarcane bagasse on the properties of incorporated red ceramics was investigated. Mixtures of kaolinitic clay from the municipal area of Campos of Goytacazes-RJ were prepared with additions of 0, 5 and 10% in weight of ashes from sugarcane bagasse. Ashes with different particle sizes lower than 149 μm (100 mesh), 75 μm (200 mesh) and 44 μm (325 mesh), were used in each incorporated composition. Specimens were 20 MPa uniaxially press-molded and sintered at 900 and 1050°C. The firing technological properties evaluated were diametrical shrinkage, water absorption and mechanical strength by diametrical compression. The results showed that the ash incorporation caused significant changes in the ceramic properties.