The interest of the zinc content of amniotic fluid and its relationship to different maternal and fetal parameters is recent. It was reported that the zinc content of amniotic fluid increases in the course of pregnancy probably as an indirect indicator of an increased rate of protein synthesis. These considerations and the known important metabolic role of zinc led us to study the zinc content of amniotic fluid and its importance in the growth and development of the fetus. Amniotic fluid samples of 24 women with normal pregnancies and normal term deliveries were studied. The samples were obtained between weeks 29 and 42 of gestation by transabdominal amniocentesis and the zinc content was determined by means of atomic absorption spectrophotometry. The zinc content of amniotic fluid increases significantly during the third trimester. A positive linear correlation was found between the zinc concentration of amniotic fluid and fetal weight and length. Fetal growth and development would depend on the zinc available due to its biological functions and thus the increase of zinc concentration of amniotic fluid in the last weeks of gestation and its correlation with fetal weight and length. These results suggest that the determination of zinc content of amniotic fluid can be useful in the assessment of fetal development and well-being, and of course of pregnancy.