Aim In order to reduce the risk of neural tube defects (NTDs) and iodine deficiency in pregnancy, the National Health and Medical Research Council recommends that pregnant women supplement their diet with folic acid and iodine. This study aimed to identify the knowledge, attitudes and practices of pregnant women regarding intake of these nutrients in order to assess whether women are adequately exposed to this health message. Methods One hundred and fifty-two conveniently sampled pregnant women residing in a regional area of New South Wales, Australia, completed a pretested questionnaire on knowledge and practices regarding nutritional supplement use during pregnancy and dietary sources of folic acid and iodine. Results Eighty-two per cent of women reported using supplements during their pregnancy, with the majority (67.7%) taking supplement brands containing both folic acid and iodine. Supplement use was significantly higher among women in the highest household income category (30.8 vs 69.2%; P = 0.001). Seventy-six per cent of the participants correctly identified NTDs to be associated with inadequate intake of folic acid, whereas only 40% correctly identified health problems associated with inadequate iodine intake. Women's knowledge of dietary sources of folic acid and iodine was limited. Conclusions A third of the pregnant women surveyed were not adhering to clinical recommendations for supplement use during pregnancy, and many had knowledge deficits with regard to the need for an adequate dietary intake of folic acid and iodine from both food and supplements during pregnancy.