The Dean and Stark distillation is an appropriate method for the determination of water in coal tar, bitumen and petroleum-like products. This article shows, however, that a direct application of the Dean and Stark method for the determination of water in biomass-derived liquid fuels results in incorrect estimates. Inaccuracies are due to the presence of soluble organics in the aqueous phase, which apparently form azeotropic mixtures with water and xylene and which condense and are trapped as distillate in the graduated cylinder. Instead, a Karl Fischer determination of water is recommended in the case of biomass-derived liquid fuels