Few studies have been conducted examining the genuine sleep condition and memory in patients with euthymic bipolar disorder. Thus we evaluated sleep complaints and memory functions in psychotropic drug-free euthymic patients with bipolar disorder. Methods: Twenty-two psychotropic drug-free euthymic patients with bipolar disorder and 44 healthy controls matched by age and sex were recruited and assessed using the Pittsburgh Sleep Quality Index (PSQI) and the Wechsler Memory Scale–Revised (WMS-R). Results: The quality of sleep and memory function of the euthymic patients with bipolar disorder were significantly poorer than those of the controls. Both years of education and the hypnotic use sub-item of the PSQI were significantly correlated with visual memory index of the WMS-R. Conclusion: Sleep complaints management is important in euthymic patients with bipolar disorder.