SummarySerum samples from 224 Norwegian cats were analyzed for the presence of feline leukemia virus (FeLV) p27 common core antigen, and for antibodies to feline immunodeficiency virus (FIV). Ninety specimens originated from the serum bank at the central referral clinic at the Norwegian College of Veterinary Medicine, which had been collected during the years 1983–1989; 67 sera were submitted from veterinarian practitioners; while 67 sera originated from cats presented for euthanasia. The cats were classified into one “healthy” and one “sick” group.Only 2.2 % of sick cats and 1.2 % of healthy cats showed FeLV antigenemia, a finding which is lower than which has been reported from many other countries.The prevalence of FIV antibodies was 10.1 % in sick cats and 5.9 % in healthy cats. Antibodies to FIV was most prevalent in male cats (14.7%) than in female cats (2.1 %), and more prevalent among domestic cats (12.0 %) compared to pedigree cats (2.4 %). Antibodies to FIV in the cats demonstrated increasing prevalence with increasing age. It may be concluded that FeLV causes minor problems in Norwegian cats, while FIV is present in a similar prevalence to what is reported form other