Background: In recent years, the incidence of missed miscarriage tended to increase; its prevalence becomes more than 3% of all pregnancies. Although chromosomal abnormalities are implicated in approximately 50% of all spontaneous miscarriages, the remaining 50% may be preventable and related to environmental factors. Objectives: To determine the risk factors for missed miscarriage among women attending the emergency room and outpatient clinic at Ain-Shams University Maternity hospital. Method: A Case control study was carried out among 130 women with normal pregnancies and 130 cases of missed miscarriage. Data were collected using a structured interviewed questionnaire. Anthropometric measurements were performed, and Ultrasonography was done to all participants to confirm the diagnosis of missed abortion. Results: Age, Hypercoagulation of blood, DM, PCO, Practicing physical exercise, using mobile phone for long time and fast food are independent significant predictors for missed miscarriage in the studied pregnant women. Conclusion: Missed Abortion is linked to many modifiable risk factors which could be easily prevented and hence decrease maternal morbidity & mortality; the researchers recommend further work to confirm these findings in other study populations.