Abstract This work presents a review of the literature about the influence of pa-rameters such as temperature and time reaction, alcohol type, alcohol: fat molar ratio, catalyst type and concen-tration, mixed intensity, as well as free fatty acid and moisture concentration, on biodiesel production yield in chemi-cal and biological transesterification of animal fats. It was found that the alco-hol: fat molar ratio required by animal fat transesterification depends on the fat and the type of catalysis that are used in the process. It was also found that, under atmospheric pressure, the temperature must be below 50 °C in biocatalysis, 80 °C in homogeneous catalysis, and 250 °C in heterogeneous catalysis. Additionally, lipase from P. cepacia bacteria is the most widely used in biocatalysis of animal fats. It was also found that yield for beef tallow is between 50-95% (reaction time: 0.75-3 h); in the case of chicken fat, between 33-99% (0.5-1.5h); for fish oil, between 76-98% (0.17-1.5 h); for duck tallow, between 75-97% (3 h); for sheep tallow, between 90-98% (24 h), and, for pork tallow, 97% (0.3 h).