In this work, the compatibilization of a poly(epsilon-caprolactone) with a number-average molecular weight of 120,000 g/mol (PCL120) and maize starch was investigated by the addition of a chemically modified poly(epsilon-caprolactone). Two types of blends were prepared by melt extrusion. In type A blends, low-molecular-weight compatibilizers; were used: (1) a poly(epsilon-caprolactone) with a number-average molecular weight of 10,000 g/mol that was reacted with maleic anhydride to obtain chains terminating in carboxylic groups and (2) low-molecular-weight poly(epsilon-caprolactone)s (number-average molecular weights of 600 and 2000 g/mol) with one pendant carboxylic group within the chains. With these groups of blends, tensile testing and scanning electron microscopy demonstrated that the compatibilizers were generally effective in inducing a better dispersion for a 60/40 poly(epsilon-caprolactone)/maize starch blend with a compatibilizer, improving the mechanical properties in comparison with uncompatibilized blends. The blends with 30% starch were not improved by the addition of compatibilizer, and this may be related to the rheology of the blends during preparation. In type B blends, high-molecular-weight compatibilizers were prepared through the grafting of variable amounts of acrylic acid or maleic anhydride to PCL120 chains. The best compatibilizer action was obtained with 0.7 wt % maleic anhydride grafted to PCL120 because both the dispersion and mechanical properties were further improved in comparison with uncompatibilized blends and type A blends. (c) 2008 Wiley Periodicals, Inc.