Vaginal bleeding in first trimester is most common complication of pregnant women. The ratio of vaginal bleeding in pregnant women is 20-25%. About 50% of pregnant women experiencing vaginal bleeding in first trimester have viable pregnancy. 50% cases of abortion are reported in first trimester vaginal bleeding. Therefore, it is necessary to evaluate the significance of ultrasonography in diagnosis of first trimester vaginal bleeding. Objective: Objective of the study is to elaborate the fundamental role of ultrasonography in first trimester vaginal bleeding. The ratio of misdiagnosis in putatively nonviable pregnancy will be reduced by complete understanding of ultrasonography significant. In this way the premature interventions can be avoided that ultimately leads to mismanagement. Study Design: It was an observational study with statistical approaches, conducted in BKMC / MMC, Mardan for the duration of six months from December 2020 to May 2021. Methods: All the antenatal women having complaint of first trimester vaginal bleeding visited the hospital was included in this prospective observational study. Those who met the inclusion and exclusion criteria set by the Gynecology department of Hospital were followed for further analysis study. Results: Out of the 90 patients included in the study, 51% cases were of threatened abortion among viable pregnancies and 6% cases of normal pregnancy were reported. Various types of abortion were reported in the patients, out of which 11% cases were of missed abortion, 1% of complete abortion, and 11% of incomplete abortion, 5% of ectopic pregnancy and 10% of blighted ovum. The inevitable abortion cases were 3% and 1.1 % cases of hydatidiform mole. Conclusion: After developing better understanding of correlation between ultrasonography and first trimester vaginal bleeding, sonologist can elaborately explain the cause of vaginal bleeding. For the diagnosis of first trimester vaginal bleeding ultrasonography is the non-invasive imaging technology.