Chronic kidney disease (CKD) is well known in older cats. In most cases, the underlying cause is never identified. CKD appears more common in young male cats and feline immunodeficiency virus (FIV) is also common in these cats, raising the question of whether the two are related. To investigate a potential association between chronic kidney disease and FIV in cats in Australia, a case-control study was designed. The study included 73 cats with CKD and 69 cats with no evidence of CKD. All cats were tested for FIV antibodies and information on age, breed and gender was gathered. The cats were divided into two age groups – under 11 years old and over 11 years old. Statistical analysis was performed to investigate any relationship between CKD and FIV, and with the other variables. Among cats under 11 years old, those with CKD were significantly more likely to be infected with FIV than cats without CKD. It was not possible to determine if infection with FIV occurred before the cats developed CKD. The role of FIV in the development of CKD disease requires further research. [SL]