Heavy hydrocarbon oils of high paraffin content are catalytically cracked using zeolite beta. The paraffin content of the oil is at least 20 weight percent or higher. The gasoline cracking products have a high octane rating and the higher boiling products a decreased pour point resulting from the dewaxing activity of the zeolite beta. The use of cracking temperatures above 500.degree. C., preferably above 550.degree. C., also improves iso-butene production.