The potency and efficacy of an inactivated oil-emulsion influenza vaccine against infection, illness, and virus shed was studied in market turkeys. No undesirable local or systemic reactions occurred following vaccination. The vaccine induced measurable antibody to nucleocapsid and hemagglutinin antigens of the virus. Challenged unvaccinated controls experienced airsacculitis, but none of the vaccinates were affected. The percent of the birds shedding virus following intranasal challenge was lower in the vaccinated groups than in the controls, and the quantity of virus shed was also smaller in vaccinated groups than in the controls.