At present, the understanding of the pathogenesis of polycystic ovary syndrome (PCOS) has advanced significantly, and improvements have been made in the treatment of PCOS symptoms. These achievements are to some extent the result of studies on experimental animals. However, a fully convincing animal model for study of polycystic ovaries, or of PCOS as whole, has not been established. This review article discusses several rat models for PCOS. Characteristics with respect to ovarian morphology, serum levels of LH, FSH, estradiol and androgens have been described and similarities to PCOS in women are discussed. The large number of the animal models for PCOS is a result of difficulties in induction of all pathological conditions similar to those seen in human PCOs. Two important considerations should be made that concern the development of an animal model for PCOs. Firstly, what is the main purpose of the model: study of ovarian morphology in PCOs or study of human disorders? Secondly, there is no reason (and probably even a possibility) for creation of an "universal" PCOS animal model. The multifactorial etiology of the syndrome justifies such a point. Depending on what PCOS-related disorder is investigated, the most suitable animal model should be used.