This study was designed to investigate the transforming impacts of tra
nsnational immigration of the Mixtec (an indigenous community from the
Mexican State of Oaxaca) on their personal health belief systems. Spe
cific interest was focused on beliefs in omens (presagios) and health
beliefs as measured by the Locus of Illness Control (LIC) instrument.
Two convenience samples, a Mexican Mixtec (or National) sample in Mexi
co and a Transnational sample residing in rural California, were inter
viewed and responded to the Locus of Illness Control instrument. Analy
ses of results, including statistical procedures, revealed significant
differences between the two samples in relation to the number and typ
e of omen beliefs, and especially in relation to the dimensions of ext
ernality and internality and prevention and cure as measured by the LI
C. The phenomenon of migration was clearly the primary factor associat
ed with the change in the belief systems. Migrants to California revea
led a much more pronounced external control profile, suggesting that T
ransnational respondents see the power for control and prevention of i
llness as lying more outside themselves than do the National group. Im
plications of this finding for health professionals and others are dis
cussed.