Infectious virus was isolated from both porcine and bovine zona pellucida-intact embryos that had been exposed to the Indiana strain of vesicular stomatitis virus (VSV) and then washed. The amount of virus isolated from embryos depended on their initial exposure level. Porcine embryos always retained more virus than bovine embryos. When embryos were cultured for 24 h after viral exposure and washing, the number of embryos carrying VSV and the amount of virus on each of the embryos was reduced. Trypsin (0.25%) was also found to be effective in inactivating/removing the VSV from embryos, suggesting that most, if not all, of the virus was bound to the zona pellucida.