Introduction: Infective endocarditis remains one of the challenging diseases to treat despite the great advance in medicine. In fact it is the fourth leading fatal infectious disease worldwide. Neurologic complications markedly influence the disease outcome and worsens the disease associated morbidities and mortalities significantly. Many neurologic embolizations remain silent. Intracranial mycotic aneurysms in particular remain mostly silent until catastrophic rupture occurs. Such rupture is associated with mortality rates reaching up to 90%.Aim of the work: To study the true incidence of acute CNS embolization in infective endocarditis; including those which are clinically silent using routine CTA. Also to study clinical characteristics of patients with acute brain embolization comparing them to those without brain embolization.Patients and methods: The study was carried out over a period of 2 years between july 2007- July 2009. The study included all definite lt. sided endocarditis patients referred to the endocarditis service, Cardiology Department, Kasr El-Aini teaching Hospitals. Total patient population no. was 31. Diagnosis of infective endocarditis was based on modified Duke criteria.Results: Acute brain embolizations occurred in 18 patients. Nine patients had CTA evidence of acute brain embolization with no clinical evidence. The most diagnosed silent lesion was mycotic aneurysm being diagnosed in 6 patients, silent brain infarction was diagnosed in 2 patients, and silent subdural hematoma was diagnosed in another one. Clinically symptomatic brain embolizations were mostly infarctions with mycotic aneurysm diagnosed in only one symptomatic patient. There was no difference regarding clinical characteristics, or complications among patients who did or did not develop brain embolization.Conclusion: Routine CTA resulted in diagnosing silent brain embolization in 9 (29%) of the whole study population. Routine CTA resulted in modification in treatment plan in 25.8% of the study population.