Abstract: Zika virus (ZIKV) is an emerging mosquito-borne virus that is associated with severe congenital brain malformations in the fetus and Guillain-Barré syndrome in adults. However, there are currently no drugs or preventive vaccines approved for ZIKV infection. Here, ciclesonide has been found significantly against ZIKV activity by plaque and cytotoxicity assays in vitro, and its 50% effective concentration (EC₅₀) to ZIKV SZ01 and MR766 are (0.40±0.22) and (1.59±1.08) μmol·L^-1, respectively. Its 50% cytotoxic concentration (CC₅₀) to Vero cells are (64.70±7.33) μmol·L^-1; Virus yield reduction and Western blot assays showed that ciclesonide can inhibit replication of ZIKV. In addition, ciclesonide can also inhibit the replication of ZIKV in A549 cells; the results of time of drug addition analysis indicated that ciclesonide mainly acts on the ZIKV RNA synthesis stage. Ciclesonide can also inhibit the internalization of ZIKV. These results indicated that ciclesonide is a potential drug against ZIKV.