Objective To observe the in vitro effect of leptin, alone or in combination with tumor necrosis factor-alpha (TNF-α) on inducible nitric oxide (NO) and on inducible matrix metallo-proteinase-1 3 (MMP-13) in rabbit articular chondrocytes. Methods The chondrocytes from the articular cartilage of 2-month-old rabbits were cultivated and identified, and the second filial generation chondrocytes were cocultured on plates with different concentrations of leptin alone or in combination with TNF-α for 48 h or 96 h after 12 h starvation. The concentration of NO and MMP-13 was measured in the chondrocytes culture supernatant fluid. The results were statistically analyzed. Results There was no significant difference in the concentrations of NO between the different concentrations of leptin alone groups and the blank control group (P ＞ 0. 05). In combination with the same concentration of TNF-α (10 ng/mL), leptin could dose-dependently increase the concentration of NO in the chondrocytes culture supernatant fluid in vitro. There was significant value in average concentration of MMP-13 on the main effect of both time and dose (P ＜0. 05) . No MMP-13 was detected in the blank control group. Conclusion Leptin can induce MMP-13 and have synergistic induction effect on NO with TNF-α in rabbit articular chondrocytes in vitro.