A simple scale for quantifying English use among Mexican Americans was constructed from four brief questions which proved to have excellent scaling characteristics by Guttman Scalogram Analysis in two independent data sets. Construct validity was established by significant associations of the scale with ethnicity, place of birth, generation within the United States, and type of neighborhood. Highly significant associations were found between scale scores and use of oral contraceptives, parity, "fatalism" regarding health, and attitudes toward folk healers. These associations remained significant (though weak) after controlling for education and family income. The language scale thus appears to be reliable and valid, to be capable of distinguishing meaningful subsets among the Mexican American population, and to be applicable to health care investigation.