This paper examines the incidence of the mismatch of the educational attainment and the occupation of employment, and the impact of this mismatch on the earnings, of high-skilled adult male immigrants in the US labor market. Analyses for high-skilled adult male native-born workers are also presented for comparison purposes. The results show that over-education is widespread in the high-skilled US labor market, both for immigrants and the native born. The extent of over-education declines with duration in the US as high-skilled immigrants obtain jobs commensurate with their educational level. Years of schooling that are above that which is usual for a worker's occupation are associated with very low increases in earnings. Indeed, in the first 10 to 20 years in the US years of over-education among high-skilled workers have a negative effect on earnings. This ineffective use of surplus education appears across all occupations and high-skilled education levels. Although schooling serves as a pathway to occupational attainment, earnings appear to be more closely linked to a worker's occupation than to the individual's level of schooling.