The objective of this descriptive study was to examine the vitamin and mineral supplements safety beliefs and practices of Iranian pregnant women. Data were collected from 400 randomly chosen women. More than 50% of the participants believed that taking vitamins and minerals during pregnancy was safe; 87% reported taking iron during pregnancy, of which 71.7 % reported their doctor as the main recommender; 21.8% reported first trimester as the most beneficial time for iron supplementation, 13.0% second trimester and 3.0% third trimester. Although an appropriate intake of vitamins and minerals can assure health in pregnancy, excess can be harmful. Educational programmes for women of childbearing age are necessary.