The flower of chrysanthemum, used worldwide as a medicinal and edible product, has shown various bioactivities, such as anti-inflammatory, antioxidant, anti-tumorigenic, and hepatoprotective activities, as well as cardiovascular protection. However, the effect of Chrysanthemum morifolium Ramat. on the regulation of osteoclast differentiation has not yet been reported. In this study, we aimed to investigate the inhibitory effect of Chrysanthemum morifolium Ramat. water extract (CME) on RANKL-induced osteoclast differentiation in mouse bone marrow-derived macrophages (BMMs).