The techniques of detecting white spot syndrome associated baculovirus (WSBV) by in situ hybridization are already well established. A DNA probe specific to PmNOB III, an isolate of WSBV from Penaeus monodon, was labeled with digoxigenin and used to detect WSBV DNA in experimentally infected wild shrimps, crabs and lobsters that are native to Taiwan. WSBV could be detected in tissue sections of all examined specimens by in situ hybridization. In marine shrimps, Trachypenaeus curvirostris, Metapenaeus ensis and Exopalaemon orientalis, WSBV DNA positive cells were observed in the gills, stomach, cuticular epidermis, antennal gland, hepatopancreas, compound eye, muscle, heart and reproductive tissues. WSBV DNA was observed only in the gills, cuticular epidermis and hepatopancreas in the freshwater shrimps Macrobrachium sp. and Procambarus clarkii. In crabs Portunus sanguinolentus and Charybdis granulata, WSBV DNA could be detected in the gills, stomach, hepatopancreas, muscle and reproductive tissues. In lobsters Panulirus versicolor and Panulirus penicillatus, the positive cells were observed in the gills, stomach, cuticular epidermis and hepatopancreas.