In this work, the influence of additives of iodinated hydrocarbons trifluoroiodomethane (CF3I) and 1-iodoperfluoropropane (C3F7I) on shock-induced ignition of acetylene and methane was experimentally investigated. The observed temperature dependencies of induction times indicate that both suppressants show noticeable inhibiting activity in acetylene, but reduce the ignition delay time in methane, similarly to previously studied halogenated fire suppressants CCl4, CF3H, and C2F4Br2.