A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) is a family of peptidases. They comprise 19 members, and have several vital functions in organism. ADAMTS-9 with aggrecanolytic activity is responsible for the degradation of the articular cartilage components like aggrecan. Adiponectin is the most abundantly secreted adipokines (adipocytokines), and the characteristic of adiponectin is controversial. It was assumed that adiponectin has anti-inflammatory effect. However, recent studies showed the inflammatory features of adiponectin. It was aimed to evaluate the effect of adiponectin on ADAMTS-9 gene expression in human chondrocytes. Human articular chondrocytes were cultured and exposed by adiponectin at 1, 4, 8 and 12 µg/ml doses. At the end of the incubation, total RNA was reverse-transcribed by random primer. The expression levels of the ADAMTS-9 and β-actin genes were determined using real-time polymerase chain reaction. The ADAMTS-9 gene expression was found to increase after adiponectin incubation at 12 µg/ml dose. The interleukin-1β induced ADAMTS-9 gene up-regulation and the increased serum level of ADAMTS-9 in patients with osteoarthritis (OA) were reported before. Similarly, the putative involvement of adiponectin in OA and rheumatoid arthritis (RA) was demonstrated. Together with these findings, our results suggesting that adiponectin may involve in the degradation of aggrecan by increasing ADAMTS-9 gene expression.