Infections with bacteria have become a serious problem in joint arthroplasty. This study reports about in vitro antibacterial activity and in vitro cell compatibility of poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers loaded with metallic silver particles of a size of 5-13 urn. In vitro antibacterial activity against Staphylococcus aureus and Klebsiella pneumoniae was studied by microplate proliferation tests. The adhesion, viability, and proliferation properties of fibroblasts (NIH 3T3) and differentiation of osteoblasts (MC3T3-E1) were clone to study in vitro cell compatibility of the scaffolds. As the results, only silver-containing PHBV nanofibrous scaffolds showed a high antibacterial activity and an inhibitory effect on the growth of both Staphylococcus aureus and Klebsiella pneumoniae bacteria. The nanofibrous scaffolds having silver nanoparticles <1.0% were free of in vitro cytotoxicity. To sum up, the PHBV nanolibrous scaffolds having nanoparticles <1.0 wt % showed not only good antibacterial activity but also good in vitro cell compatibility. It is considered that the PHBV nanofibrous scaffolds with silver nanoparticles <1.0 wt % have a potential to be used in joint arthroplasty.