The dehydrocyclization of a feed containing one or more acyclic hydrocarbons capable of undergoing ring closure to provide aromatic hydrocarbons is accomplished by contacting the feed under dehydrocyclization conditions with a zeolite L dehydrocyclization catalyst which is substantially free of zeolite T and which contains at least one Group VIII metal component, thereby converting at least a portion of the acyclic hydrocarbon content of the feed to aromatic compound(s). Use of the foregoing zeolite L dehydrocyclization catalyst has been found to result in less non-selective hydrocracking of naphtha range materials to gaseous hydrocarbons and greater conversion of low octane paraffins to high octane aromatics than that achieved with a zeolite L synthesized by a prior procedure which results in the co-production of zeolite T contaminant.