Sera from 292 cats were analyzed by means of indirect immunofluorescence for antibodies to Bartonella henselae, B. quintana and B. elizabethae. The sera were sent to the Swedish National Institute of Veterinary Medicine for health monitoring and were tested retrospectively for antibodies to Bartonella. The most prevalent antibodies (25%) reacted with the B. elizabethae antigen. Cats with such antibodies were older than those without antibodies. The prevalence of antibodies to B. elizabethae was higher in the south of Sweden than in the north, with the highest prevalence (46%) being found in cats living in the Stockholm region. There was no difference in sex distribution. A low prevalence (1%) of antibodies to B. henselae was found and no sera reacted with B. quintana. The high prevalence of antibodies to B. elizabethae is consistent with previous findings in Swedish patients. The small number of cats with B. henselae antibodies observed in this study could be due to the cold climate and the low occurrence of cat fleas in Sweden.