Existing evidence demonstrates that sleep structure varies across the menstrual cycle in healthy women (1). These variations could be more severe in women suffering from premenstrual dysphoric disorder (PMDD) (2). In a previous study of healthy women, subjective sleep quality was shown to be constant across both phases of the menstrual cycle (3). The current study aims to test whether there exists a variation in subjective sleep quality of PMDD sufferers across the follicular and luteal phases of the menstrual cycle