Polycystic ovary syndrome (PCOS) is a common condition for women patients to seek traditional Chinese medicine (TCM) treatment. However, the pathogenic mechanisms of PCOS have not been completely understood, and it may involve complex interactions of various factors such as genetics, hormones, metabolism and the environment. Besides, clinical manifestations of PCOS includes menstrual irregularity, menorrhea and infertility. This case report describes a patient whose menstrual period extended to 2 months and after underwent TCM treatment for approximately six months with herbal medicine exclusively, the patient subjectively experienced a trend towards normal menstrual period. On the other hand, objective laboratory data before and after treatment also supports our therapy. This case suggests that TCM treatment alone may achieve certain efficacy in patients with PCOS, providing valuable insights for further discussion among healthcare professionals.