Background: Hyperemesis gravidarum (HG), a disorder characterized by ongoing severe nausea and vomiting with resulting ketosis, affects 0.3–2% of women during pregnancy. Helicobacter pylori (H. pylori) infection is one of the most common and endemic human infections worldwide, causing a number of very common and important gastrointestinal problems. Objective: We aimed to find the association between H. pylori infection and hyperemesis gravidarum. Patients and Methods: This prospective case control study was conducted at Manshiet El-Bakry General Hospital from October 2020 till June 2021 and performed on 32 patients who had a clinical diagnosis of hyperemesis gravidarum in the first trimester and 32 normal pregnant women who served as control group < /p> Results: Our results revealed that Helicobacter pylori stool antigen was significantly more frequent in hyperemesis gravidarum group. Conclusion: As evident from the current study, there was a strong association between H. pylori infection and HG, allowing us to conclude that H. pylori should, therefore, be considered as one of the risk factors of HG pointing to H. pylori as one contributing factor of this complication of pregnancy. H. pylori testing should be included in investigations of HG, especially when the condition does not respond to treatment and in cases continuing past the first trimester. Appropriate therapeutic non-teratogenic regimens for eradication of H. pylori could be considered to relieve the symptoms of HG in some intractable cases.