The panela industry is one of the most important Agro Industries in Colombia, making it the largest per- capita consumer and the second largest producer worldwide. The fuel used in this process is traditionally the sugarcane bagasse (SB) which is a byproduct of milling. However, due to the low efficiency of panela furnaces additional fuel is required such as wood, used rubber tires and coal. The fixed-bed furnaces inefficiency is mainly due to incomplete combustion of SB caused by the influence of process variables. Therefore, the aim of this work was to study the influence of particle size (PS) and moisture content (MC) over the combustion stages of SB in fixed-bed furnaces. A three-level factorial design was proposed for PS and MC of SB where the temperature and gas concentration were considered as response variables to evaluate the furnace performance. The results obtained in this work show that if the MC increases then the SB yield in the combustion is decreased. On the other hand, the increasing PS can counteract the effect of the MC of SB.