In this study, the production of biodiesel from the fat that extracted from beef tallow waste using alkali-catalyzed transesterification was investigated. Two methods of transesterification were employed including single-step transesterification (SSTE) and two-step transesterification (TSTE). In both methods, KOH or NaOH with methanol was used. The reactions were performed at two temperatures (32 and 60 °C) for a fixed duration that is 1 h. The fuel properties of the produced biodiesel were assessed. The results indicated that, both methods of the transesterification were successful to enhance the fuel properties of the tallow as compared to the direct use of it as a fuel. Besides, the values of the assessed properties met the specified limits according to the ASTM standards. Thin layer chromatography was used for monitoring the transesterification reaction of the optimal biodiesel sample using a silica gel plate. Furthermore, blending of the optimum biodiesel sample with petro-diesel was made using different volume percentages (10, 20 and 30 %). The results disclosed that biodiesel had a slight influences on the assessed properties of petro-diesel.