Regulatory T (T(reg)) cells are the major arbiter of immune responses, mediating actions through the suppression of inflammatory and destructive immune reactions. Inappropriate T(reg) cell frequency or functionality potentiates the pathogenesis of myriad diseases with ranging magnitudes of severity. Lack of suppressive capability hinders restraint on immune responses involved in autoimmunity and alloreactivity, while excessive suppressive capacity effectively blocks processes necessary for tumor destruction. Although the etiology of dysfunctional T(reg) cell populations is under debate, the ramifications, and their mechanisms, are increasingly brought to light in the medical community. Methods that compensate for aberrant immune regulation may not address the underlying complications; however, they hold promise for the alleviation of debilitating immune system-related disorders. The dominant immunoregulatory nature of T(reg) cells, coupled with recent mechanistic knowledge of natural immunomodulatory compounds, highlights the importance of T(reg) cells to practitioners and researchers of complementary and alternative medicine (CAM).