Background Poor maternal nutrition adversely affects pregnancy and birth outcomes. In many societies, there are dietary restrictions due to misconceptions or food taboos during pregnancy which consequently results in the depletion of important nutrients. These cultural malpractices and beliefs can influence the dietary intake of pregnant women which subsequently affects the birth outcome. The study aimed at exploring the extent of food taboos and misconceptions during pregnancy in rural communities of Illu Aba Bor Zone, Southwest Ethiopia. Methods A qualitative study was conducted using an in-depth interviews of key informants and focus group discussions among purposively selected pregnant women and their husbands, health care workers, health extension workers, and elderly people. Data were transcribed verbatim, thematized; color-coded, and analyzed manually using the thematic framework method. Result Thorough reading and review of the transcripts generated three major themes. The primary theme was the belief and practice of taboos related to the intake of certain food items during pregnancy. Pregnant women, their husbands, and mothers-in-law believed that certain foods should be avoided during pregnancy. The second theme was foods that were held as taboo and the reason attached to it. The most common food items held as taboo were related to the consumption of vegetables like cabbage, pumpkin, milk and milk products, sugar cane, fruits like bananas and avocado and egg. The main reasons to avoid these foods were beliefs that it can be plastered on the fetal head, making fatty baby which is difficult for delivery. The third theme was the reasons underlying adherence to food taboos which is deeply embedded in the person's believes and attitudes of the pregnant women, who were nested within the influence of the social environment surrounding them and the traditional beliefs and values of the society in general. Conclusions The results showed a widespread practice of food taboos during pregnancy in the study area. The finding suggested that there is a need for strengthening the nutrition counseling components of antenatal care follow-up and planning comprehensive nutrition education through involving important others to dispel such traditional beliefs and prevent food taboo practices in the study community.