Hydrophobic polyesters have been synthesized in miniemulsion in the presence of large amounts of water. The yield of the esterification and the molecular weight of the polyesters have been determined for different reaction conditions. It was found that the dispersion state has no influence on the equilibrium: the yield is the same in 100 nm particles than in very large droplets. However, an important parameter is the water concentration inside the particles, as shown by an increase in the yield with more hydrophobic monomers. Another important parameter is the structure of the alcohol monomer. Alcohol compounds bearing electron-donating groups allow to displace the equilibrium toward ester formation. It is also shown that polyester/polystyrene hybrid particles can be synthesized in a very simple way using a one pot procedure. (C) 2003 Elsevier Science Ltd. All rights reserved.