We examined the use of polymerase chain reaction (PCR) in investigating suspected cases of meningococcal infection in Birmingham. Data held by Birmingham Health Authority were interrogated to determine cases of suspected or confirmed meningococcal infection for a 3-year period from April 1996. The microbiology departments of five local hospitals completed a standard proforma about the microbiological investigation of cases and included details of patient age, clinical presentation and method of confirmation of the clinical diagnosis. Of 273 cases, 123 had PCR performed on either cerebrospinal fluid and/or blood. Groups more likely to have a PCR done were those presenting with septicaemia alone, and those in the 5–14 year age group. In 33 cases, PCR was the only positive microbiological result. Over the study period there was increasing but variable use of PCR in the investigation of meningococcal infection and PCR increased the yield of confirmed cases.