The objective of this study was to assess the knowledge and use of folic acid among pregnant women in Omdurman Maternity Hospital, Sudan. The study is a descriptive cross-sectional hospital-based study. One thousand pregnant women were interviewed, where a structured questionnaire was developed for the study. Results of the survey indicated that 91.2% of the women knew about folic acid, 16.2% knew that it prevents birth defects, 86.9% knew that it prevents anemia. The majority (88.6%) of women was taking the supplement, 51.3% were taking it regularly, but only 4.7% took it before getting pregnant. Knowledge and use were significantly influenced by age, education level, employment and family income. Preconception use of the supplement was lowest among illiterate and least educated women 7.02%. It was concluded that a high level of knowledge of folic acid was not reflected in regard to successful use of the folic acid supplement. Thus, it is justifiable for the prevention of all those affected by low levels of FA intake to introduce the policy of food fortification as is practiced in many developed countries.