It was the aim of the present work to evaluate Rickettsia typhi antibody prevalence in 'Comunidad Autónoma de Madrid' (CAM), an area in the centre of Spain. A total of 640 serum samples from the general population were tested by an indirect immunofluorescence assay. Specific R. typhi antibodies were found in 44 (6.8%) of the samples. The present survey results demonstrate the occurrence of R. typhi human infections in this area.