The authors report a study on 10 human fetuses aged between 9 and 16 weeks of gestation. A PAP technique (peroxidase-anti-peroxidase) was used to identify the time and place of growth hormone appearance. Data obtained show intense positivity for chondrocytes, obleoblasts and perichrondrium. Hepatocytes were also found to be positive. These results suggest that GH plays an important role in a number of tissues in which it conditions maturation and development.