Nausea and vomiting may occur in as many as 90% of pregnancies, whereas hyperemesis gravidarum (HG) represents a more severe condition and is potentially lethal if not treated. HG affects 0.5–2% of all pregnancies, and is defined as persisting nausea and vomiting leading to dehydration, weight loss and nutritional deficiencies starting before the 22nd week of gestation. The aim of the study was to identify the prevalence and risk factors of hyperemesis gravidarum among pregnant women at the Woman's Health Center, Assiut University, Egypt. A cross sectional research was used in carrying out this study. The sample consisted of 94 pregnant women with Hyperemesis Gravidarum who were admitted to the Antenatal Inpatient Wards at the Woman's Health Center for one year. The results of this study explored that the prevalence of Hyperemesis Gravidarum at the Egyptian Woman’s Health Center was 4.5%. As regards the current antenatal risk factors that aggravate hyperemesis gravidarum, the highest percentage (26.6%) of women had gastrointestinal diseases. Moreover, (19.1%) had more than one factors and more than one sixth (16%) had urinary tract infection. Three quarters of women diagnosed with hyperemesis gravidarum admitted to the hospital for the first time and 94.6% of them admitted at the first trimester. In the light of the present study findings, it can be concluded that the overall hospital rate of hyperemesis gravidarum at the Woman’s Health Center, Assiut University, Egypt was 4.5% which was considered a high prevalence in relation to the universal prevalence of hyperemesis gravidarum. The most common risk factors of hyperemesis gravidarum were gastrointestinal diseases, urinary tract infection and multiple pregnancy. A larger study is needed to establish the different prevalence and risk factors of Hyperemesis Gravidarum on large number of population among different Maternity Health Care Setting. An exploration of high prevalence of Hyperemesis Gravidarum recommended that the physicians and maternity nurses should pay more attention to these women who were diagnosed with Hyperemesis Gravidarum.