Pregnant women in methadone maintenance therapy may have poor nutrition during pregnancy. In 2006-2008, methadone-treated pregnant women (n = 22) were recruited at an urban academic medical center and compared with nondrug-using pregnant women (n = 119) at 20-35 weeks' gestation. We measured adiposity using prepregnancy body mass index (BMI), dietary intake using a food frequency questionnaire, and micronutrient and essential fatty acid status using biomarkers. Methadone-treated women had lower BMI, consumed more calories, had lower serum carotenoid concentrations, and higher plasma homocysteine concentrations than controls. The study's limitations and implications for future research are discussed.