A baculovirus of Penaeus plebejus for which the authors propose the name Plebejus Baculovirus (PBV) was found in postlarval and juvenile P. plebejus from a hatchery and grow-out pond in New South Wales, Australia. Subspherical eosinophilic inclusion bodies, mostly single or in pairs, were in hypertrophied nuclei of the hepatopancreas and mid-gut epithelial cells. Electron microscopy revealed a crystalline lattice of periodicity 20 nm inclusion bodies. Virions up to 440 nm long, both free and occluded in the inclusion body, were scattered in the nuclei. The capsid envelope contained 2 electron-dense layers.