Introduction : About one fourth of pregnant women present with bleeding in the rst trimester .The four major sources of nontraumatic bleeding in early pregnancy are ectopic pregnancy, miscarriage (threatened, inevitable, incomplete, complete), implantation of the pregnancy, cervical, vaginal, or uterine pathology (eg, polyps, inammation/infection, trophoblastic disease). Although 50% of cases presenting with vaginal bleeding continue to have a normal healthy pregnancy, but the maternal anxiety about risk of miscarriage should be assessed and counselled. The present study is an overview of etiologies and evaluation of bleeding upto 12 weeks of gestational age. Aim:To evaluate the incidence and etiology of rst trimester bleeding. Objective: To correlate the association between rst trimester bleeding and miscarriage. Methodology:A retrospective study among pregnant women with rst trimester bleeding was conducted for a period of 1 year at Chettinad hospital and Research Institute.Detailed History taking and pelvic examination was done for 139 patients.Specic blood investigation along with Transvaginal USG probe 3-5 MHz was performed and appropriate treatment was given. Results: Out of 900 pregnant women attending the out patient (OP) over a period of one year, 139 patients presented with rst trimester bleeding , incidence being 15.44%. The present study suggest that 41.007% women had miscarriage following rst trimester bleeding . It is depicted that 20.14% of women had history of previous abortions and 12.23% had history of bleeding in previous pregnancy. The major cause of bleeding in the rst trimester in our study was threatened abortion (32.37%). Conclusion :We conclude that the present study helps in giving appropriate treatment to women presenting with rst trimester bleeding . Ultrasonography plays a key role in the diagnosis of cause of bleed . Early care and close monitoring will inevitably improve pregnancy outcome .