Bacterial plaque has been established as the primary etiologic factor for the initiation of periodontal disease. However it has been shown that without a susceptible host, the periodontal pathogens are necessary but not sufficient for disease to occur. Hence, the systemic factors/conditions of the host must be understood since they may affect disease prevalence, progression and severity. Among these, several hormones have been suggested as important modifying factors that may influence the pathogenesis of periodontal diseases. Hormones are specific regulatory molecules that modulate reproduction, growth and development and maintainence of the internal environment, as well as energy production, utilization, and storage. Hormonal effects reflect physiological/pathological changes in almost all types of tissues of the body.