In this study, we observe the developing cortex of the fetal adrenal gland in one hundred normal Human fetuses (71 males and 29 females) over a period of two and half years in various stages of development. Subsequently, we correlate the light microscopic studies of the fetal adrenal gland with respect to its development and functional activity. Moreover, the width of definitive and fetal cortices is noted and its ratio for the respective gestational age is calculated. The ratio of the measurements of width of definitive cortex and fetal cortex remains constant i.e. 1:4 at all stages of development; consequently, it can be suggested that the definitive cortex is continuously proliferating and adding cells to fetal cortex where the cells become differentiated and functional. After functioning for some time, the fetal cortical cells must be degenerating. Further, the fetal cortex comprises 80% of adrenal cortex till birth. The cells of the fetal cortex show vacuolated cytoplasm indicating a steroidogenic activity as early as 15-16 weeks of gestation and acts as an endocrine gland throughout the gestational period. Finally, we affirm and compile the development of the cortex in various gestational stages.