A hydrocarbon upgrading process is described in which a hydrocarbon feed is treated in at least one of a steam cracker, catalytic cracker, coker, hydrocracker, and reformer under suitable conditions to produce a first stream comprising aliphatic and aromatic hydrocarbons. A second stream comprising C6-C9 aliphatic and aromatic hydrocarbons is recovered from the first stream and aliphatic hydrocarbons are removed from at least part of the second stream to produce an aliphatic hydrocarbon-depleted stream. The aliphatic hydrocarbon-depleted stream is then dealkylated and/or transalkylated and/or cracked (D/T/C) by contact with a catalyst under suitable reaction conditions to produce a third stream having an increased benzene and/or toluene content compared with said aliphatic hydrocarbon-depleted stream and a light paraffin by-product. Benzene and/or toluene from the third stream is then methylated with a methylating agent to produce a xylene-enriched stream.