In just a few years C-reactive protein (CRP) has become an important test in the rapid elucidation of infections in Norwegian general practice. 33 general practitioners in the southern part of Vestfold county, continuously registered 546 consultations where a CRP analysis was performed. The protein was analyzed in 10% of all the consultations (range 3-31%). The general practitioners stated that the CRP analysis has great diagnostic impact in the elucidation of acute infections, but significantly less impact in routine examinations. The result contributed to a change in diagnosis in 30% of the patients where a diagnosis involving infection was considered. C-reactive protein contributed to a reduction in the prescribing of antibiotics in a quarter of the consultations. C-reactive protein is an important supplement to clinical investigation in the elucidation of infections in Norwegian general practice.