The World Health Organization (WHO) publishes technical guidance on the quality, safety and efficacy of vaccines intended to assist national regulatory authorities and manufacturers. As part of its programme, WHO convened an informal consultation to initiate revision of the WHO recommendations on the production and control of inactivated Japanese encephalitis (JE) vaccines for human use, at its headquarters in June 2006. The attendees included experts from national regulatory authorities, national control laboratories and manufacturers from around the world as per WHO policy to include all relevant stakeholders in the standards development process. Issues pertaining to recent development with inactivated JE vaccines were presented and discussed. Participants agreed upon the scientific basis of revised specifications and the inclusion of new sections on nonclinical and clinical evaluation of inactivated JE vaccines. It was agreed that the revision would cover both existing vaccines derived from mouse brain or primary cell cultures and vaccines under development in a continuous cell line (Vero).