Purpose: To present an opposing view to the recent conclusions reached by the Practice Committee of the American Society for Reproductive Medicine and a recent review of the role of progesterone in subfertility by Sonntag and Ludwig that there is no evidence to support using progesterone in the luteal phase as exclusive therapy. Materials and Methods: A large quasi randomized study not mentioned by either review is presented. Results: In this study published in 1989 when women with luteal phase deficiencies and subfertility were evaluated for follicular maturation, the majority seemed to form mature follicles. This majority group found far better with pregnancy outcome by taking exclusive progesterone in the luteal phase than follicle maturing drugs. A recent prospective series confirmed its beneficial effect. Conclusions: Physicians should not empirically treat with follicle maturing drugs but should use progesterone in the luteal phase, preferably in those women who seemingly create a mature follicle.