BACKGROUND; About 2–5% of adolescent girls present with primary amenorrhea which is absence of menstruation . Materials and methods; This retrospective single centred study was conducted in Department of obstetrics and Gyenocology, Nilratan Sircar Medical College . 46 cases of primary amenorrhoea from August 2017 to December2018 were included and cases were analysed according to history,physical examination,hormone profile, pelvic USG, MRI, and karyotype where necessary. Results; The common causes of primary amenorrhoea were mullerian anomalies (23 cases, 50%), hypogonadotropic hypogonadism (10 cases, 21%) and Hypergonadotropic hypogonadism (7 cases, 13%) . Karyotype was performed in 20 patients and 8 cases showed abnormal karyotype. Definitive treatment was done accordingly. Conclusion; Depending on its cause ,failure to attain menarche may lead to varying clinical sequalae. Timely evaluation of a broad differential diagnosis have important implications for emotional, physical and reproductive health in young women.