Definitely, usual sludge drying methods adversely affect the yield of extracted lipids as well as the lipid saponifiable matter, consequently reducing the potential for biodiesel production. FAME composition of biodiesel is also modified, too. Among the methods tested, oven drying at 105 °C could be the best option for subsequent biodiesel production, giving 15.7% of biodiesel produced from a dried sludge basis. Unfortunately, thermal drying is not cost effective for a large scale application