Objective：To study clinical features of four cases of oral contraceptive pills（OCPs） induced pseudo-Cushing’s syndrome and to review the literature related to cortisol assay affected by OCPs. Methods：The clinical features of the four childbearing age fe－male patients，who have taken OCPs due to oligomenorrhea，were analyzed retrospectively. The cross-reactivity between OCPs and serum total cortisol were analyzed retrospectively. Results：Elevated serum total cortisol was found in four patients while taking OCPs. Serum total cortisol of three patients returned to be normal after OCPs discontinuance. Based on the results of equal dilution，the cross-reactivity of serum total cortisol in OCPs was insignificant. OCPs may affect serum total cortisol in two ways as reported in the litera－ture：estrogen increases cortisol-binding globulin，causing elevated serum total cortisol；OCPs may directly stimulate the hypothalamic-pituitary-adrenal axis to generate cortisol. Conclusion：OCPs may result in pseudo-Cushing’s syndrome by a variety of mechanisms. Clinicians should pay attention to this issue to avoid misdiagnosis and mistreatment.