Common variable immunodeficiency syndrome (CVID) includes a heterogeneous disorder characterized by reduced levels of IgG, IgA or IgM, and recurrent bacterial infections with normal T-cell immunity in 60% of patients. It affects the gastrointestinal tract as the largest immune organ with a wide spectrum of symptoms and signs. We present a case of nodular lymphoid hyperplasia (NLH) of the small intestine in a 31-year-old man admitted for evaluation of chronic diarrhea. Upper and lower gastrointestinal endoscopy revealed multiple polyps in the stomach, duodenum, ileum, and large intestine mimicking familial adenomatous polyposis (FAP). Although he had no history of recurrent infection, immunological profiles were in favor of CVID. We emphasize the importance of considering CVID in any patient with gastrointestinal manifestations even in the absence of recurrent bacterial infections. Diagnostic delay results in more morbidity and complications in untreated patients.