A process is described for alkylating benzene contained in a refinery gasoline stream, in which the refinery gasoline stream is contacted with an alkylating agent comprising one or more C2 to C5 olefins in an alkylation reaction zone under alkylation conditions to produce an alkylated effluent. The alkylation reaction zone comprises at least a first alkylation reaction stage and a second alkylation reaction stage and a portion of said alkylating agent is fed to each of said first and second alkylation reaction stages so that, although the molar ratio of alkylatable aromatic to alkylating agent in the total feed to the alkylation reaction zone is less than 1, the molar ratio of alkylatable aromatic to alkylating agent at the inlet of each of the first and second alkylation reaction stages is at least 1.0..