This report summarises information collected for the surveillance of influenza virus infection in England and Wales from October 1995 to June 1996 (weeks 40/95 to 25/96). Total respiratory disease' activity, as reported by the Birmingham Research Unit of the Royal College of General Practitioners, rose to peaks in weeks 48/95, 51/95, and 01/96. The first peak coincided with a peak in "influenza and flu-like illness'. The subsequent peaks were accounted for by an increase in reports of acute bronchitis, including bronchiolitis, and may have been associated with the annual rise in infections with respiratory syncytial virus. Influenza A virus was responsible for most infections, with moderate activity occurring in the early part of the winter, peaking in December (week 48/95). Influenza A subtype H3N2 predominated until week 07/96, after which subtype H1N1 accounted for most infections. Influenza activity was first seen in central and northern England, followed by the south of England, Wales, and Scotland. Circulating influenza viruses were antigenically similar to the components of the 1995/96 vaccine. International surveillance during 1995/96 has led to a different H3N2 component being included in the influenza vaccine recommended for 1996/97.