In this work, steam reforming of animal fat was studied using a downflow fixed bed reactor. Tests were performed with an emulsion of 40% fat and 60% water. Mass flow rate and temperature effects were evaluated in the range of 1.2 g/min to 2.9 g/min and 750 °C to 950 °C, respectively. Gas chromatography was used to analyze the gas sample from the gasifier to determine the contents of H2, CO, CH4, CO2, C2H4, and C2H6. Carbon and hydrogen conversion efficiencies, dry gas yield, cold gas efficiency, and higher heating value of producer gas were determined. The results showed that mass flow rate and temperature are operating conditions that determine the composition of the gas obtained and the performance of the gasification process. The gasification parameters increased with the temperature rise, since the best results were obtained at the highest tested temperature. The increase in the operating mass flow contributes to a decrease in the overall performance of the gasification process.