AIM: To describe the clinical and histological characteristics of a group of adults with small-bowel nodular lymphoid hyperplasia (NLH).METHODS: Patients were searched for five years in pathology records of our institution. The biopsy material was reassessed using strict histopathological criteria.Clinical data were obtained from medical records.RESULTS: Small-bowel NLH was diagnosed in 18 cases.The female: male ratio was 2: 1. The most frequent symptoms were diarrhea (72%), involuntary weight loss (72%) and abdominal pain (61%). Nine patients (50%)had immunodeficiency. Small-bowel bacterial overgrowth was found in three (17%) cases. At small-bowel NLH diagnosis, three (17%) had associated lymphoma: two intestinal and one extra-intestinal lymphomas. In two patients with villous atrophy and anti-endomysial antibodies the diagnosis of celiac disease was established.Giardia lamblia infection was found in only one patientwith hypogammaglobulinemia (Herman's syndrome).CONCLUSIONS; NLH is uncommon in adult patients.Associated diseases are immunodeficiency and lymphoid tissue malignancies.