Ebolaviruses (EBOV) cause severe disease with a recent outbreak in West Africa in 2014-2015 leading to more than 28 000 cases and 11 300 fatalities. This emphasizes the urgent need for better knowledge on virus-host interactions of these highly pathogenic RNA viruses. Host innate immune responses, including the interferon (IFN) system play a key role in restricting the spread of a viral disease. Previously, EBOV VP35 has been shown inhibit RIG-I and PKR pathways, while VP24 is capable of directly binding to activated STAT1/STAT2 complexes thus efficiently inhibiting the expression of IFN-induced genes. In the present study we systematically analysed the effects of cloned EBOV genes (VP24, VP30, VP35, VP40, NP and GP) on the main host immune response to RNA viruses: the activation of RIG-I pathway and type I and III interferon (IFN) gene expression. EBOV VP24, in addition of inhibiting the expression of IFN-induced MxA gene, was also found to efficiently inhibit type I IFN-beta and III IFN-lambda1 gene expression. VP24 inhibited deltaRIG-I, MAVS, IKKe, TBK1 and IRF3-5D (constitutively active form of IRF3) activated IFN-beta/lambda1 promoter-reporter expression in transfected HEK293 cells. Thus, VP24 mediated inhibition of IFN gene expression was found to occur downstream of IRF3 activation and to be dependent on VP24 importin binding residues. These results emphasize the importance of VP24 in EBOV infection cycle, making VP24 as an excellent target for drug development.