Adiponectin is an adipokine that is specifically expressed in adipose tissues, directly sensitizes the body to insulin via specific receptors and its decreased plasma concentration is responsible for insulin resistance in obese humans. Diabetes is an important problem also in veterinary medicine, and feline diabetes is very similar to human type 2 diabetes, in which obesity is an important risk factor. In the present study, We obtained cDNA clones corresponding to feline adiponectin and adiponectin receptor 1 (AD-R1), whose nucleotide and deduced amino acid sequences were highly identical to those of other species, especially, the extra-cellular domain of feline AD-R1 was almost identical to that of human AD-R1. Adiponectin mRNA was exclusively detected in the adipose tissue, but AD-R1 was in all tissues tested in this study. Next, plasma samples were collected from 22 cats visiting veterinary practices. They were divided to 2 groups based on a five-point scale body condition score (BCS), such as normal group (BCS ranged from 2.5 through 3.5) and obese group (BCS ranged from 4.0 through 5.0). Plasma adiponectin in obese cats (7.2 ± 1.5 μg/ml) was significantly lower than that of normal cats (18.0 ± 3.2 μg/ml). These results suggest that adiponectin may be responsible for insulin function also in the cat, and it can be a target molecule for treatment of obesity and diabetes in cats.