-The depletion of fossil fuels prompted considerable research targeting the development of alternative fuel sources. Biodiesel production has acquired increasing importance owing to its renewable nature and milder environmental impacts. To this end, alternative sources of feedstock have been sought and studies aiming at the optimization of the production procedure have been carried out. Millions of liters of waste frying oil are produced from local restaurants and houses every year, most are discarded into sewage systems damaging networks and complicating the treatment process. This study is intended to consider aspects related to the feasibility of the production of biodiesel from waste frying oils in order to alleviate the waste frying oil pollution problems as well as to reduce the cost of biodiesel production. Locally available spent vegetable oils have been collected from different sources and accordingly have somewhat different chemical compositions. The conducted experiments involved the production of biodiesel from the different feed stocks using the base catalyzed trans-esterification process. The quality of the produced biodiesel is compared to petro-diesel in terms of established standard specifications.