Amniotic fluid obtained from pregnant women who have a specific nonproject related clinical indication for amniocentesis is analyzed. One hundred eleven specimens were obtained from 103 patients between 12 and 45 weeks gestation. Zinc and copper levels, determined in duplicate with atomic absorption spectrophotometry, remained relatively flat throughout gestation. The range of values widens as gestation progresses, but there are no statistically significant correlations between concentrations and length of pregnancy. BIBLIOGRAPHIC RERERENCES: Chez, R.A., Henkin, R. I. and Fox R.: Amniotic Fluid Zinc and Copper Concentrations in Human Pregnancy, Obstet. & Gynecol., 1977 (in Press).