Background: Leptin is a hormone produced by the adipocytes that circulates into the bloodstream in free and bound forms. The leptin level in the blood plasma reflects the total energy resourse of adipose tissue. This level can change with short-term disturbances in the energy balance and changes in the concentration of certain cytokines and hormones circulating in the blood. Leptin plays an important role in the reproductive process by regulating GnRH secretion in the hypothalamus and gonadotropins in the pituitary gland. Concidering the wide distribution of leptin receptors in the body, hypotheses have been issued on both central and peripheral mechanisms involving the hypothalamic-pituitary-gonadal axis. The exact mechanism by which leptin activates neurons that secrete GnRH for the puberty and reproduction onset remains unclear. Methods: Our bibliographic analysis includes a total of 20 specialized publications, conducted in order to describe the physiological mechanism of leptin and its relationship with various reproductive disorders, as well as discussing the possibilities of using this hormone in clinical practice. Results: Leptin is necessary for normal reproductive function, but when it is in excess, it can have harmful effects on the reproductive system. Thus, leptin plays an important role in the appearing of various functional disorders in the ovaries, uterus during puberty, in women of reproductive age and in physiological pregnancy or in premature births. Leptin may also be a marker for the detection of breast cancer of reproductive age women. Conclusion: The study of the physiological and pathophysiological role of leptin enlarges our knowledge about the mechanisms that regulate neuroendocrine function, body weight and energy exchange. Understanding these mechanisms will lead to new approaches to the treatment of obesity, appetite disorders and other fertility disorders.