Low sulfur gasoline of relatively high octane number is produced from a cracked, sulfur-containing olefinic naphthas by hydrodesulfurization followed by treatment over an acidic catalyst comprising zeolite beta with a metal hydrogenation component, preferably a mild hydrogenation component such as 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. 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.