This paper presents research on synthesis and specifications evaluation of biodiesel from waste fish fat, recovered from the production processing of catfish. This is an abundant source of raw materials in the southern of Vietnam. The results show that the biodiesel synthesized from this material completely satisfies the technical specifications of biodiesel according to Vietnam standards QCVN1. Some standards of this fuel, especially the very high cetane values, show the potential of using this fuel in mixing with traditional diesel. Analysis of FAME component of this fuel also shows that the main components of biodiesel from waste fish fat are C16:0 and C18:1, which are very good components for diesel fuel, not only it does improve the combustion efficiency, but also the fuel\'s oxidation stability and pour point are improved. The results have also found a simple biodiesel synthesis process based on a one-stage transesterification reaction with a methanol reaction agent using an alkaline KOH as catalyst. The efficiency of biodiesel recovery is 87% although the acid value is relatively high, 4mgKOH/g oil.