Results from several studies support associations among variants in electroencephalogram (EEG) alpha voltage, alcohol dependence, ethnic heritage, and a family history of alcohol dependence, although no studies have as yet been conducted in individuals of Hispanic ethnicity. Categorization of EEG, by using spectral analyses, into high-, medium-, and low-voltage alpha, as well as absolute EEG power in alpha and beta frequency ranges, was carried out for Hispanic American (n=108) and white non-Hispanic American (n=269) young adult men and women (age range, 18 to 25 years) who had a family history, but no personal history, of alcohol dependence. Eighteen percent (n=70) of the participants were categorized as having a low-voltage alpha EEG, 16% had high-voltage alpha, and 64% had medium-voltage alpha. In comparison with findings for men, women were found to have higher overall power in the low frequency alpha (7.5-9 Hz) and beta (12-20 Hz, 20-50 Hz) frequency ranges. Hispanic Americans had a lower percentage of individuals in the low-voltage alpha group (9%) and more individuals in the medium-voltage alpha group (73%) compared with findings for white non-Hispanic Americans (low-voltage alpha, 19%; medium-voltage alpha, 62%). Results of the current study confirm the presence of ethnic stratification in EEG alpha variants.