Background Albeit constituting the majority of the gastrointestinal (GI) tract, malignancy of the small bowel is rare. It is often detected at more advanced stages of disease, after the onset of life-threatening complications such as small-bowel obstruction (SBO) or perforation. The small bowel is a common site of secondary neoplastic involvement. Primary malignancy of the lung (PML), breast, cervix and colon have all been associated with metastasis to the small bowel. In contrast, PML is responsible for only 0.2-2 percent of GI metastasis. Case Report A man in his 60s presented with a 2-month history of upper abdominal pain, vomiting and 5kg weight loss. Abdominal CT showed features of SBO likely due to a lesion within the small bowel. The provisional diagnosis was a primary small bowel malignancy with pulmonary metastasis. Due to his symptoms of SBO, a decision was made to proceed straight to surgery. A cicatrising mass was identified in the terminal ileum and a small bowel resection was performed. Histopathology confirmed the lesion as poorly differentiated adenocarcinoma with immunohistochemistry staining confirming lung origin. The patient was promptly referred to medical oncology, where he was started on pembrolizumab (programmed cell death protein 1 inhibitor) treatment. Discussion This case underlines the importance of considering metastatic lesions of PML to the small bowel in patients with abdominal signs and symptoms. Metastatic spread of primary lung cancer to the bowel is rare and often represents advanced disease. It can be complicated by SBO, perforation and sepsis. Surgical intervention including emergency bowel resection can avoid life threatening complications and obtain a sample for tissue diagnosis.