Malnutrition, particularly among pregnant women, represents a major public health challenge in Burkina Faso due to its negative impacts on maternal and child health. This study aimed to analyze the level of knowledge of pregnant women attending antenatal care (ANC) regarding maternal nutrition. It specifically assessed their knowledge of the three food groups, the principles of a balanced diet, the consequences of malnutrition during pregnancy, and iron–folic acid supplementation. This was a quantitative, crosssectional, and descriptive study with prospective data collection, conducted from March 1 to April 30, 2024, at the Guimbi Ouattara Primary Health Care Center (CSPS) in BoboDioulasso. Data were collected using the Kobocollect application and analyzed with SPSS and Excel software. A composite indicator, the Maternal Nutrition Knowledge Index (MNKI), based on five domains, was developed to facilitate the analysis and interpretation of the results. The findings indicate a moderate overall level of maternal nutrition knowledge, with a global MNKI of 62.8%. Although most participants demonstrated good practical skills in composing a balanced meal, significant gaps remain regarding the identification of food groups, the recommended duration of iron–folic acid supplementation during the postpartum period, and the understanding of the consequences of inadequate nutrition during pregnancy. Women with no formal or low educational attainment, those living outside the health facility catchment area, and primigravidae in early pregnancy emerged as the most vulnerable groups, highlighting the need to strengthen targeted nutrition education and behavior change communication interventions.