OBJECTIVES: To determine whether the nasopharyngitis prodrome of meningococcal disease is caused by the disease itself or respiratory viral coinfection. METHODS: Case control study of children with suspected meningococcal disease. Nasal swabs and a respiratory history were obtained from suspected cases and matched controls. Molecular testing for 12 respiratory viruses was used. RESULTS: 104 suspected cases and controls were recruited. Detection rates for respiratory viruses were 27% (28/104) for suspected cases and 29% (30/104) for controls. Rhinoviruses (43/58, 74%) and adenoviruses (14/58, 24%) occurred most frequently with 3 coinfections. 39 (38%) suspected cases were confirmed as meningococcal disease with a detection rate for respiratory viruses of 26% (10/39). No significant difference was found in the respiratory viral detection rate between this group and their controls, Odds ratio=1.0 (95% CI 0.3 to 3.3). Prodromal respiratory symptoms were significantly more likely for suspected cases (77/104, 74%) than controls (55/104, 53%), Odds ratio 2.8 (95% CI 1.4 to 6.0), but were equally common in confirmed (28/39, 72%) and unconfirmed cases (49/65, 75%), Odds ratio 0.8 (95% CI 0.3 to 2.3). CONCLUSIONS: This study found no evidence that respiratory viral infections contribute to the prodrome of meningococcal disease. Rhinovirus and adenovirus detection by nasal swab is common in well and unwell children.