Glucocorticoids have been used in the treatment of prostate cancer to slow disease progression, improve pain control and offset side effects of chemo-and hormonal therapy. However, they may also have the potential to drive prostate cancer growth via mutated androgen receptors or glucocorticoid receptors (GRs). In this review we examine historical and contemporary use of glucocorticoids in the treatment of prostate cancer, review potential mechanisms by which they may inhibit or drive prostate cancer growth, and describe potential means of deifning their contribution to the biology of prostate cancer.