Many agents have been suggested to elicit sarcoidosis, and, recently, an association was presented between this disease and the bacterium Rickettsia helvetica. The aim of this study was to investigate if serological support for such an association could be detected. Sera from 20 well-characterised sarcoidosis patients were investigated for anti-rickettsial immunoglobulin G antibodies with a micro-immunofluorescence technique. R. helvetica, R. conorii and R. typhi served as antigens. In conclusion, none of the investigated sera displayed detectable titres of anti-rickettsial immunoglobulin G antibodies. Thus, the current study does not support an association between rickettsia and sarcoidosis.