Background: Euphorbia hirta possesses antibacterial, anti-inflammatory, galactogenic, antidiarrheal, antioxidant, hypoglycemic, antiasthmatic, antiamebic, antifungal, and antimalarial activities. Objective: The overall objective of the current study was the investigation of the whole plant extract of E. hirta and flavonoids from E. hirta on gastroesophageal reflux disease (GERD) in rats. Materials and Methods: The whole plant extract of E. hirta was characterized by analysis of flavonoids (HPLC: HPLC, UV, IR, MS and 1HNMR). GERD model was induced surgically in Wistar rats under pentobarbitone sodium anesthesia (50 mg/kg, i.p.) and the tissue esophagus and stomach were removed. The tissues were washed with physiological saline and were examined for GERD. The whole plant extract of E. hirta in doses of 50, 100, and 200 mg/kg were administered orally twice daily at 10:00 and 16:00 hours, respectively, for 5 days and kaempferol (100 mg/kg) or omeprazole (OMZ) in the dose of 30 mg/kg 1 hour prior to the induction of GERD. Control groups received suspension of 1% carboxymethyl cellulose in distilled water (10 mL/kg). Results: The levels of gastric wall mucus increased and of plasma histamine and H+, K+ ATPase significantly decreased in groups treated by both the plant extract and flavonoids. Both the plant extract and flavonoids reduced the lipid peroxidation and superoxide dismutase and increased the levels of catalase and reduced glutathione. Conclusions: The whole plant extract of E. hirta is attributed to its antisecretory, gastroprotective, and antioxidant potential as that of quercetin, rutin, kaempferol, and proton pump blocker (omeprazole) to treat GERD.