Several polyesters were synthesized from ethylene glycol, glycerol and adipate, succinate dimethyl esters. Immobilized Candida antarctica lipase B was used as catalyst for 6 h under vacuum at 70 degrees C without any further solvents. The highest conversion rate of 88.5% occurred for the polymerization of poly(ethylene adipate), evaluated by H-1 NMR. MALDI-TOF analysis indicated that most of the oligomers formed were dimers or tamers. After successfully synthesize the polyesters we set-up the optimal conditions for their in-situ coating onto cotton substrates with a soluble lipase from Thermomyces lanuginosus. This work presents a novel bio-approach to impart hydrophobic properties to coated cotton-based fibre materials.