Aiming the development of high-performance biodegradable polymer materials, the properties and the processing behavior of poly(3-hydroxybutyrate), P(3HB), and their blends with poly(ε-caprolactone), PCL, have been investigated. The P(3HB) sample, obtained from sugarcane, had a molecular weight of 3.0 x 10 5 g.mol, a crystallinity degree of 60%, a glass transition temperature (T g ), at -0.8 °C, and a melting temperature at 171 °C. The molecular weight of PCL was 0.8 x 10 5 g.mol -1. Specimens of 70/30 wt. (%) P(3HB)/PCL blends obtained by injection molding showed tensile strength of 21.9 (± 0.4) MPa, modulus of 2.2 (± 0.3) GPa, and a relatively high elongation at break, 87 (± 20)%. DSC analyses of this blend showed two Tg´s, at -10.6 °C for the P(3HB) matrix, and at -62.9 °C for the PCL domains. The significant decrease on the T g of P(3HB) evidences a partial miscibility of PCL in P(3HB). According to the Fox equation, the new T g corresponds to a 92/8 wt. (%) P(3HB)/ PCL composition.