Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst, preferably a catalyst comprising an intermediate pore size zeolite, such as ZSM-5, and a large pore size zeolite, including a metal hydrogenation function, such as a faujasite, preferably USY, which contains nickel and molybdenum. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. Use of the intermediate pore size zeolite and the large pore size zeolite is expected to provide more boiling point conversion than either zeolite alone under the same conditions.