Casticin, an active compound isolated from Vitex rotundifolia L., was reported to possess anti-inflammatory activity. However, the effect of casticin on inflammatory response in human osteoarthritis (OA) chondrocytes remains unclear. In the current study, we examined the anti-inflammatory effects of casticin on chondrocytes exposed to interleukin-1β (IL-1β). Our results demonstrated that casticin treatment significantly improved cell viability in chondrocytes exposed to IL-1β. Casticin significantly inhibited IL-1β-induced NO and PGE2 production, and iNOS and COX-2 expression in human OA chondrocytes. It also suppressed the levels of TNF-α and IL-6, as well as decreased production of MMP-3, MMP-13, ADAMTS-4 and ADAMTS-5 in IL-1β-stimulated chondrocytes. Furthermore, casticin prevented IL-1β-induced NF-κB activation in chondrocytes. Taken together, these findings showed that casticin attenuates inflammatory responses in chondrocytes stimulated with IL-1β, possibly through the NF-κB signaling pathway. Thus, casticin may serve as a potential anti-inflammatory agent in the treatment of OA.