Mitochondria play an essential role in intracellular energy metabolism. This study described the involvement of Bombyx mori nucleopolyhedrovirus (BmNPV) GP37 (BmGP37) in host mitochondria. Herein, the proteins associated with host mitochondria isolated from BmNPV-infected or mock-infected cells by two-dimensional gel electrophoresis were compared. One mitochondria-associated protein in virus-infected cells was identified as BmGP37 by liquid chromatography-mass spectrometry analysis. Furthermore, the BmGP37 antibodies were generated, which could react specifically with BmGP37 in the BmNPV-infected BmN cells. Western blot experiments showed that BmGP37 was expressed at 18 h post-infection and was verified as a mitochondria-associated protein. Immunofluorescence analysis demonstrated that BmGP37 localized to the host mitochondria during BmNPV infection. Furthermore, western blot analysis revealed that BmGP37 is a novel component protein of the occlusion-derived virus (ODV) of BmNPV. The present results indicated that BmGP37 is one of the ODV-associated proteins and may have important roles in host mitochondria during BmNPV infection.