Background: Tinosopora cordifolia ( Willd) (TC) is commonly used in Ayurvedic medicine since long time for number of ailments and its preparations are also considered by food safety and standards authority of India as nutritional supplement. However the scientific evidence on its possible safety and efficacy in polycystic ovarian syndrome and associated complications was not studied in detail. Objectives: The purpose of this investigation is to examine whether or not TC can have therapeutic effects on letrozole induced PCOS and related complications such as body weight, dyslipidaemia, glucose tolerance, hormonal regulation, insulin resistance and sensitivity, severity of PCOS and histopathological changes in ovary using mice animal model. Design: Present study is a preclinical study involving laboratory animals. Methods and analysis: After verifying the absence of PCOS, the animals began receiving Letrozole, which lasted for 21 days. Fasting blood glucose (FBG), the oral glucose tolerance test (OGTT), triglycerides, cholesterol, and weight were recorded. The levels of hormones like oestrogen, progesterone, insulin, testosterone, luteinising hormone (LH) and follicle stimulating hormone (FSH), histopathology was carried out. Ethics: The Institutional Animal Ethics Committee at DITU gave its clearance to the animal experimentation on July 10, 2021 (DITU/IAEC/21-22/07-06). Discussion: The majority of cornified epithelial cells were seen in groups treated with TC extract during the estrous phase of the cycle. Mice exposed to TC retained normal body weight. FBG, 1- and 2-hour OGTT, triglyceride and cholesterol levels were all significantly improved by extracts. Estradiol, progesterone, testosterone, insulin, LH and FSH concentration were all corrected in TC-treated animals. The HOMA-IR, HOMA-Beta and QUICKI values were also corrected with TC extracts. The morphological and microscopic features of the ovary were also greatly enhanced. Based on these findings, we conclude that treating PCOS mice with TC extracts significantly ameliorates the disease and severity down to nil-to-moderate levels by reducing hyperinsulinemia, hyperandrogenism, dyslipidaemia, enhancing insulin sensitivity, correcting oestrogen, progesterone, LH and FSH levels via enhanced ovarian function. Further molecular and cellular level of study is recommended for further elaboration of mechanism of action. Plain language summaries • Tinospora cordifolia satva, oil and hydroalcoholic extract were studied in letrozole-induced PCOS in mice model • Anti PCOS efficacy of 3 preparations studied with respect to their mechanism of action in detail • For the first time proposing method of calculating severity of PCOS in animal model • Tinospora cordifolia oil preparation completely reversed PCOS effect of letrozole and made them normal • Histopathological and morphological studies support the biochemical claims