Studies of the transesterification reaction of vegetable oils are of key importance in the development of a country's national economy. By optimizing the conditions of the biodiesel preparation process it is possible to achieve significant savings of energy resources and raw materials, thus reducing the end product cost. The decrease in the price of biodiesel will encourage consumer interest and demand, ensuring further development of domestic resources and production to meet transportation requirements. In the biodiesel industry, homogeneous alkaline catalysts such as NaOH, KOH and NaOCH3 are used most widely. These catalysts provide high transesterification reaction yield and ester content with a minimal reaction time. Usually after the biodiesel production process homogeneous alkaline catalysts that are in high concentration in the crude biodiesel and glycerol, are neutralized by using mineral acids and isolated in the form of salts. These additional operations and consumption of raw materials significantly increase the cost of biodiesel production. Use of effective heterogeneous catalysts for the transesterification reaction in biodiesel production would enable the development of a no-waste technology and hence result in an economic benefit. CaO is a common local ingredient in Latvia that is derived from the limestone and can be used as heterogeneous alkaline catalyst in a transesterification reaction of vegetable oils or animal fats.