With energy prices reaching historical highs, biodiesel as an alternative fuel is increasingly attracting attention. Currently, biodiesel is made from a variety of feedstocks, including pure vegetable oils, waste cooking oils, and animal fat; however, the limited supply of these feedstocks impedes the further expansion of biodiesel production. Microalgae have long been recognized as potentially good sources for biofuel production because of their high oil content and rapid biomass production. In recent years, use of microalgae as an alternative biodiesel feedstock has gained renewed interest from researchers, entrepreneurs, and the general public. The objective of this publication is to introduce the basics of algal-biofuel production and the current status of this emerging biodiesel source. Current Feedstock for Biodiesel Production Biodiesel can be made from any oil/lipid source; the major components of these sources are tricylglycerol molecules (TAGs, figure 1). In general, biodiesel feedstock can be categorized into three groups: