BACKGROUND Gastric heterotopia is a benign entity found throughout the gastrointestinal tract but is rarely identified in the rectum. Since 1939, only 94 cases have ever been identified, and it can present as a mass formation with symptomatology that mimics colorectal malignancy. In some instances, malignancy has been shown to arise within rectal gastric heterotopia. Here, we present 3 cases from the past 20-year period of rectal gastric heterotopia at a single tertiary institution. CASE REPORT A 25-year-old man (case 1), a 58-year-old woman (case 2), and a 33-year-old man (case 3) were found to have polypoid mass-like lesions greater than 1.0 cm within the rectum. Following biopsy, pathology showed gastric oxyntic mucosa flanked by colorectal mucosa, thus indicating gastric heterotopia. Presenting symptoms from all patients consisted of unspecified anal pain, hematochezia, or a combination of both. All patients were treated with endoscopic mucosal resection (EMR), which provided relief of symptoms and confirmed no evidence of invasive malignancy. CONCLUSIONS Rectal gastric heterotopia can mimic malignancy and in very rare instances can harbor high-grade dysplasia as well as invasive carcinoma. EMR seems to be a definitive treatment that offers relief to patient symptomatology and reassurance that any dysplasia is identified and removed.