Rationale:Intramural gastric abscess is a rare clinical condition. It is frequently neglected because of the absence of specific clinical symptoms and misdiagnosed due to the difficulty in differentiating a benign lesion from a malignant one on the gastric wall. Several imaging techniques are helpful for identifying an intramural gastric abscess. Nevertheless, a definite diagnosis is still challenging, and unnecessary surgery is sometimes performed. Therefore, more information regarding case experiences should be shared to help correctly diagnose intramural gastric abscesses.Patient concerns:Two patients, a 47-year-old woman and a 31-year-old man, were hospitalized for abdominal pain.Diagnosis and interventions:In addition to routine blood tests, either two or three imaging examinations, including esophagogastroduodenoscopy (EGD), computed tomography (CT), and endoscopic ultrasonography (EUS), were performed for these patients. The first patient was diagnosed with gastric cancer metastasized to the gastrocolic ligament, and the other was suspected to have a gastric wall abscess secondary to cancer of unknown origin. Both patients underwent surgery.Ourcomes:Surgery revealed a gastric wall abscess involving the colon in the first patient. She recovered after using oral antibiotics for 1 week, and she showed no discomfort or abnormalities during follow-up examinations. The second patient was diagnosed with gastric wall abscess derived from metastasized gastric cancer with a primary tumor located at the splenic flexure of the colon. He was discharged because of intolerance to chemotherapy and died before follow-up.Lessons:EGD, CT, and EUS/fine-needle aspiration (EUS/FNA) are extremely valuable for differentiating an intramural gastric abscess from gastric cancer, and misdiagnoses can occur if any of these assessments is ignored. Hence, we recommend performing EGD, CT, and EUS/FNA as part of the routine examination when either of these two diseases is suspected clinically.