Objective To describe pica behavior (ingestion of nonfood items) in pregnant low-income Mexicon-born women in Mexico and the United States.Design A convenience sample of informants was interviewed with a questionnaire containing open-ended and closed-ended questions. SettingA low-income community on the outskirts of Ensenada, Mexico, and clinics serving low-income people in southern California (Santa Ana, Bakersfield, andLos Angeles). Participants Of a total of 225 Mexican-born women, 75(33%) were interviewed in Ensenada, and 150 (67%) were interviewed in southernCalifornia. Results The prevalence of pica during pregnancy was 44% (n= 33) in the Ensenada group and 31% (n = 46) in the southern California group.Those who reported pica behavior more commonly had a relative who also practiced pica. Conclusion The high reported rate of pica in this sample indicates that pregnant Mexican-born women should be screened for pica and educated about the potentially serious effects on the fetus and mother.