BACKGROUND: Whipple's endocarditis is an uncommon disease, with approximately 100 cases reported to date. Case series suggest that Whipple's endocarditis usually presents without extracardiac manifestations of Whipple's disease. METHODS: We report 4 consecutive cases of Whipple's endocarditis associated with brain lesions. All patients fulfilled Duke Criteria for definite endocarditis. Whipple's disease was diagnosed through 16S rRNA polymerase chain reaction assays on valves excised from patients with culture-negative endocarditis (n=3) or through polymerase chain reaction and periodic acid staining-positive foamy macrophages on duodenal biopsy (n=1). RESULTS: All patients were male, aged 56 to 72 years. They presented with mitral (n=1), aortic (n=1), mitral and aortic (n=1), and tricuspid (n=1) endocarditis. Brain magnetic resonance imaging was performed because of mild-to-moderate cognitive disorders (n=3) or ataxia (n=1) and revealed multiple (n=3) or solitary (n=1) contrast-enhancing lesions. Cerebrospinal fluid studies revealed meningitis in 1 case. Polymerase chain reaction assays on cerebrospinal fluid were negative for all patients. All patients received intravenous ceftriaxone (2-4 weeks) associated with gentamicin (2 weeks), followed by 1 year of oral trimethoprim-sulfamethoxazole, with favorable outcomes. CONCLUSION: Whipple's associated central nervous system disease may be common but frequently undiagnosed, in patients with Whipple's endocarditis. Because treatment is different when neurologic disease is present (ie, trimethoprim-sulfamethoxazole vs doxycycline/hydroxychloroquine), clinicians should consider brain imaging in patients diagnosed with Whipple's endocarditis.