Strain F Newcastle disease virus is a virus of low virulence originally reported by Asplin (1952) in England. Since that date, the use of this virus as an immunizing agent in the form of a live vaccine, has been studied. As a result, Strain F Newcastle disease vaccine has been used in national and experimental control programs in several countries in Europe, Africa and Asia. The published literature is reviewed under the following headings: properties, viability, clinical effects of vaccination, duration of immunity and a simultaneous Newcastle disease fowl pox vaccination. This review includes 24 reports published outside North America.