The objective of this study was to assess the knowledge and use of folic acid among pregnant Arabian women in Qatar and Oman. Three hundred pregnant women were interviewed during their second trimester based on a questionnaire developed for the study. Results of the survey indicated that 94% of the women knew about folic acid, 41.3% knew it should be taken periconceptionally, 58.5% knew that it prevents birth defects and 34.4% were able to identify five or more food sources of folic acid. The majority (88.7%) of women was taking the supplement, 85.0% were taking it regularly and 13.2% took it before getting pregnant. Knowledge and use were significantly influenced by ethnicity, age, education level, employment and family income. Periconceptional use of supplement was lowest among younger women (4.9%) and illiterate and least educated women (5.3%). It was concluded that high level of knowledge of folic acid was not reflected as successful use of the folic acid supplement.