In January 1996, during an outbreak of meningococcal disease at a Hellenic Air Force recruit center in southern Greece, we collected paired serum specimens from 55 randomly selected recruits and tested for antibodies against influenza virus types A and B. Of 55 specimens, 15 (27%) were found to be positive for recent influenza B infection, confirming previous reports that respiratory tract infection due to influenza is probably a predisposing factor for meningococcal disease.