Maternal nutrition is an important determinant of birth outcome and infant health. In this study, we sought to identify the current knowledge of prenatal nutrition among women in Tucumán, Argentina, to examine the extent to which knowledge was implemented and to identify opportunities for improvement in prenatal care and education. We conducted in-depth interviews with 10 women about their eating habits during pregnancy, prenatal nutrition education and knowledge, and attitudes about nutrition and pregnancy. Four major themes were identified: incomplete knowledge or practice, lack of comprehension, cultural beliefs, and noncompliance with medical advice. Suggested interventions are discussed.