A test was developed to assess the surface activity of disinfectants against dried viral preparations. In this preliminary study a variety of disinfectants was tested against herpes virus. The results showed that 2% alkaline glutaraldehyde and 70% ethanol or isopropanol were effective in 1 min. Hypochlorite solutions (2500 ppm av. Cl2) were effective in 5 min, but povidone-iodine (10%) was slower in action and a clear soluble phenol showed uncertain activity at 5 and 10 min. High concentrations of alcohols (above 95%), two quaternary ammonium compounds and 0.5% aqueous chlorhexidine showed little activity in 10 min.