Emphysematous gastritis is a rare infection of the gastric wall with 55%-60% mortality. A 44-year-old man with AIDS, hepatitis C, and intravenous drug use presented with a 1-day history of acute-onset abdominal pain, nausea, and nonbloody, nonbilious emesis. On examination, he was afebrile without other vital sign abnormalities. He had epigastric abdominal tenderness without rebound or guarding. The peripheral-blood leukocyte count was elevated to 12.8 with 93.8% neutrophils. The patient's clinical presentation markedly improved with IV fluids and broad-spectrum antibiotic therapy. His presentation and radiologic findings, including gastric intramural air and air in the portal vein, are consistent with emphysematous gastritis. Conservative management is first-line for milder cases of emphysematous gastritis. Exploratory laparotomy and total gastrectomy are indicated only in severe cases such as transmural ischemia and peritonitis. Immune-compromised status is a predisposing factor and associated with subtler findings than the classic dramatic clinical presentation.