This article addresses studies of the developmental morphofunctional properties of areas of the prefrontal cortex of adolescents involved in visual (frontal oculomotor field 8) and speech motor (fields 44 and 45 of Broca’s area) functions, as well as the cortex in the area of the lateral surface of the frontal pole (field 10) and the medial paralimbic part of the prefrontal cortex (field 32/10). Autopsy specimens were obtained from 60 people (52 male and eight female) of three age groups: I) children from 8 to 12 years of age (n = 30), II) adolescents aged 13–16 years (n = 15), and III) young adults aged 17–21 years (n = 15). Pyramidal neuron size was evaluated in layers III and V of the cortex, along with fibroarchitectonics, specific volumes of neurons and intracortical fibers; the gliovascular index was determined. Histological methods were used, with computerized morphometric and stereological analysis. The study results showed that developmental microstructural changes in the prefrontal cortex were seen in adolescents, leading to increases in the complexity of its morphofunctional organization as compared with children.