Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment in a second step over a a first catalyst zone comprising a large pore size zeolite material and a second catalyst zone comprising an intermediate pore size material. Preferably, the large pore size material is zeolite beta and the intermediate pore size material is ZSM-5. The treatment 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. In favorable cases, using feeds of extended end point such as heavy naphthas with 95 percent points above about 380.degree. F. (about 193.degree. C.), improvements in both product octane and yield relative to the feed may be obtained.