Details of 13 new cases of inflammatory fibroid polyp of the gastrointestinal tract and of 76 patients recorded in the literature (total 89) are described and analysed. The lesion is always benign, may occur at any age but is commonest in the sixth and seventh decades, and involves the stomach most frequently. Abdominal pain, often related to obstruction, is the principal symptom. Eosinophilia of the peripheral blood does not occur. The lesions are sessile or polypoidal, originate in the gut submucosa, vary greatly in cellularity, and have a wide range of tissue eosinophilia. Some are very vascular, many of the larger vessels having a notably broad zone of connective tissue about them. The aetiology of the condition is discussed and reasons for distinguishing it from eosinophilic gastroenteritis, with which it is frequently confused, are given. The precise nature and aetiology of the inflammatory fibroid polyp remains undetermined.