An improved processing technique is provided for conversion of olefins of 2 to 4 carbon atoms to product comprising high octane gasoline components. Embodiments of the present improved processing technique include conversion of light olefins to high octane olefinic gasoline components, and conversion of light olefins to high octane aromatic gasoline components.The improved technique comprises contacting an appropriate light olefin feedstock with a catalyst comprising a crystalline aluminosilicate zeolite characterized by a silica/alumina mole ratio of at least 12 and a constraint index, hereinafter defined, within the approximate range of 1 to 12 in the presence of a relatively large amount of co-fed water. The amount of co-fed water is maintained at from about 0.5 to about 15 moles of water/mole of olefin feedstock.