Natural rubber (NR) was compounded with polyhydroxybutyrate-co-hydroxyvalerate (PHBV) to improve mechanical properties for making a composite to be used in packaging applications. Gamma radiation technique was used to improve adhesion properties between these materials. The results showed that gamma radiation could induce cross-linking between NR and PHBV. The SEM micrograph illustrated the radiated NR/PHBV blends with gamma dose 5 kGy, 10 kGy and 15 kGy presenting a good adhesion at the blend interface. The investigation by FTIR, showing the appearance of small peaks at 2950 and 2997 cm-1 related to CH3 asymmetric stretching, also confirmed the cross-linking after the exposure of the NR/PHBV blend to gamma radiation. Also, the tensile results supported cross-linking between NR and PHBV. The elongation at break of NR/PHBV blend decreased when increasing dosage of gamma ray from 0 kGy to 15 kGy. © (2013) Trans Tech Publications, Switzerland.