Whipple disease is a rare, multiorgan disease with prominent intestinal manifestations. We report a retrospective clinical study of 52 patients recruited in various parts of France from 1967 to 1994. Seventy-three percent of the patients were male. Clinical manifestations preceding the diagnosis were articular for 35 patients (67%), digestive for 8 patients (15%), general for 7 patients (14%), and neurologic for 2 patients (4%). At a later stage of the disease, 44 patients (85%) presented diarrhea, weight loss, and malabsorption, while 8 patients (15%) did not show any gastrointestinal symptom throughout the development of the disease. Forty-three patients (83%) presented arthralgia or arthritis, and 11 (21%) had prominent neurologic symptoms. In addition, cardiovascular symptoms were present in 9 patients (17%); mucocutaneous symptoms, in 9 patients (17%); pleuropulmonary symptoms, in 7 patients (13%); and ophthalmologic symptoms, in 5 patients (10%). All patients but 1 were given a positive diagnosis on histopathologic criteria: jejunal biopsy for 46 patients (90%), lymph node biopsy for 3 patients (6%), brain biopsy for 1 patient (2%), postmortem jejunal and cerebral biopsy for 1 patient (2%). With treatment, the disease evolved favorably in 47 patients (90%), while 5 patients (10%) had unfavorable outcomes (2 deaths from neurologic involvement, 1 patient with chronic dementia, and 2 patients with digestive symptoms insensitive to antimicrobial therapy). Of the 41 patients initially treated successfully and whose treatment has been completed, clinical evolution after discontinuation of treatment was favorable in 34 cases (83%). Clinical relapses occurred in 7 patients. No relapse was observed after treatment by trimethoprim-sulfamethoxazole, alone or following a combination of penicillin and streptomycin, or after the combination of penicillin and streptomycin, whatever the oral follow-up treatment prescribed. The evolution of patients showing a relapse was favorable in all cases after reintroduction of antibiotic therapy. These results are discussed in the light of previously published series and case reports of Whipple disease. The diagnosis of the disease remains difficult at an early phase or when digestive symptoms are absent. It is noteworthy that proximal enteroscopy is sometimes misleading, considered normal on macroscopic examination and nonspecific on pathologic grounds. A normal erythrocyte sedimentation rate represents another pitfall. Histopathology is the key for positive and differential diagnosis, and may require multiple and repeated biopsies. Findings from molecular biology confirm the central role of an uncultured Gram-positive bacillus which was named in 1992 Tropheryma whippelii. A recent report suggests that polymerase chain reaction (PCR) analysis of peripheral blood might allow the diagnosis of Whipple disease in some cases. However, immunologic or cellular parameters such as macrophagic function may play an important, although not clearly elucidated, role in the pathogeny of the disease. Trimethoprim-sulfamethoxazole should be considered the antimicrobial agent of choice in the treatment of Whipple disease, minimizing the risk of cerebral involvement and relapses.