The article presents the investigation of histomorphological differentiation and growth of parathyroid glands in human fetus from the second to the ninth lunar month. The longer and the shorter diameter of these glands were measured. The obtained values are compared with the development and the growth intensity of the skeleton (biparietal head diameter and femoral length of a fetus from lunar months 3 to 9) and with the role of the placenta in the mentioned processes. The results of our investigation show the concordance of the skeletal growth with the development and histomorphological differentiation of these glands. The factors involved in these processes point out the complex relationship between the mother and fetus during osteogenesis, expressed on the hormonal level, in mineral metabolism and placental activity.