Graves' disease and thyroid dysfunction during pregnancy can lead to maternal and fetal complications. No information is available on thyroid function in women with a past history of Graves' disease. We compared free T3, free T4 and TSH in a group of pregnant women with a history of resolved Graves' disease requiring no current treatment (n= 34) and in a group of pregnant controls (n= 102). We found no significant differences in the levels of these hormones between the two groups. Women with a past history of Graves' disease and no current treatment display a normal thyroid function and adaptation during pregnancy.