Poly(3-hydroxybutyrate) (PHB) is a thermoplastic polyester with a great potential owing to its biodegradability, bioreabsorbation and biological synthesis from a renewable source. Despite these characteristics, the applications of this polymer are very restricted due to its poor mechanical properties and thermal instability at temperatures above its melting point (around 175°C). Among the possibilities of improvement of these materials, the development of blends is a relatively fast and inexpensive option. Poly(epsilon-caprolactone) (PCL) is a semi-crystalline polymer that may be used as a biomaterial. It presents good mechanical properties, a low melting point (around 55 °C), and could be a good option to develop PHB blends, maintaining the biodegradability and bioreabsorption properties. The objective of the present work was to obtain blends of PHB and PCL by melting mixture in an internal mixer. The compositions varied from 0 to 30 wt% of PCL. DSC, DMA, and SEM were used to characterize the blends. The blends were found to be imiscible with no indication of interaction either the amorphous or crystalline state. The morphology shows PHB as the matrix and PCL as the dispersed phase.134138Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)