Using data obtained in December 1979 from the biennial Hired Farm Working Force Survey supplement of the Current Population Survey, case weights were applied to obtain a sample of 149 migrant farmworker case studies (selected from an estimated 217,000 migrant farmworkers) to ascertain the agricultural attachment level of migrant farmworkers in terms of employment and demographic variables. Analyses focused on three worker groups: those citing farmwork as their principal activity during the year; workers citing nonfarm work as their principal activity; and those not in the labor force during most of the year. Variables examined included age, sex ethnicity, education, days worked, wages earned, distance traveled, and major crop or livestock activity. Analyses indicated that: the primarily farmwork group was highly dependent on agriculture for the majority of their earnings, had lower total earnings than those of the primarily nonfarm work group, and were more likely to be older, household heads, and largely responsible for their families' support; and the primarily nonfarm work group used farmwork only for supplemental income, obtained only a small portion of their total earnings from farmwork, and had higher total earnings than others. Data suggested possible inaccuracies in the general image of migrant farmworkers as portrayed by the literature. Statistical tables are appended. (AH)