Hypogammaglobulinemic sprue (HGS), which may predispose to infection, is uncommon. Twelve patients (all men; median age 29 years, 15–50) with HGS (4%) of 296 with chronic small bowel diarrhea and malabsorption syndrome (MAS) during a 10-year period were analyzed. Treatment of HGS was delayed due to misdiagnosis as intestinal tuberculosis (n = 7) and diarrhea-predominant irritable bowel syndrome (n = 1). All had diarrhea and weight loss (median loss 12 Kg). Associated conditions were clubbing, bronchiectasis, and seizure (2 patients each), and hypothyroidism (n = 1). Laboratory parameters were urinary D-xylose median 0.46 g/5 g/5 h (range 0.2–1.6; normal ≥1), fecal fat 11.9 g/day (3.8–16.7; normal ≤7 g), serum IgA, IgG, and IgM: 23.5 mg/dL (17–114; normal 90–450), 584 mg/dL (145–1051; normal 800–1800), and 23 (0–40.3; normal 60–280). IgA, IgG, and IgM were low in 10, 10, and 11, respectively. Duodenal biopsy was normal in 6 patients and showed partial villous atrophy in 6 and nodular lymphoid hyperplasia in two. Associated infections were giardiasis (n = 1), disseminated strongyloidiasis (1), small intestinal bacterial overgrowth (3), septicemia (2), and septic arthritis (1). Two patients died of sepsis, five are well on immunoglobulin and specific anti-infective treatment, and five are lost to follow up. Approximately 4% patients with MAS have hypogammaglobulinemia, which is often associated with infection and is diagnosed late.