In Brazil, compounded diet pills that combine amphetamines, benzodiazepines, antidepressants, diuretics and laxatives are often prescribed. In 2006, the Food and Drug Administration banned their sale in the United States (US) citing substantial safety concerns. This study evaluates the prevalence of, and factors associated with, use of these pills among Brazilian immigrant women aged 18–50. Pill use was assessed at one clinic and two churches using an anonymous survey (n = 307). While living in the US, 18% of clinic respondents and 9% of church respondents reported using these diet pills. Nearly two thirds of pill users reported adverse effects. In multivariate logistic regression analysis, being unmarried, college educated, dissatisfied with current weight, and advised by a US physician to lose weight were associated with greater odds of imported diet pill use. To enhance care of Brazilian immigrants, US physicians should become familiar with the health consequences of imported diet pills from Brazil.