The dehydration, electrolyte and metabolic changes which occur in hyperemesis gravidarum are well recognized. The aim of this paper was to study the changes in serum copper and zinc and their correlation with the changes in serum electrolytes that occur in patients with hyperemesis gravidarum. Serum copper, zinc, sodium and potassium and urinary chloride were measured in 30 patients suffering from hyperemesis gravidarum and compared to the levels in 10 normal pregnant women in their first trimester. There was no significant change in serum copper or zinc in patients with hyperemesis compared to normal pregnant women. Also, there was no significant correlation between the changes in the level of these trace elements and the decrease which occurred in serum sodium and potassium and urinary chloride.