As the world's oil supply is gradually depleted, the need for alternative fuel sources has become more apparent. Biodiesel is a renewable, domestic alternative fuel that can be handled and used with existing infrastructure and vehicles. The biodiesel reaction is the simple transesterification of a fat or oil with a monohydridic alcohol, like methanol, in the presence of an acid or base catalyst. Performing this reaction in the microwave reactor makes it more efficient and therefore, more economically viable. We show that using a microwave field (2450MHz) cuts the reaction time to a fraction of that needed for bench-top reactions for a variety of oils. Microwave reactions performed in pressurized tubes at 50 degrees C with a 2.00min run time resulted in 89, 80, 82, and 96% yields for olive, safflower and sunflower oils and Crisco respectively. Using GC/MS we have observed that microwave reactions provide cleaner final products with fewer impurities. We have also observed that synthesis of biodiesel from soy oil using a 1:1 mixture of methanol and ethanol resulted in a 2.2:1 mixture of the methyl and ethyl esters (25W, 50 degrees C, atmospheric pressure, 87% yield). This result is in agreement with the literature for the bench-top reaction of canola oil.