We evaluated the prevalence of microembolic signals (MES) in patients with Behcet's disease (BD). We also attempted to determine the frequency of MES in ED patients with or without neurological involvement. This study enrolled 55 patients fulfilling the diagnostic criteria of International Study Group for BD. Bilateral transcranial Doppler ultrasound of the middle cerebral arteries was performed. MES were identified based on the criteria of International Consensus group on Microembolus Detection. Patients with BD were divided into two groups in respect of the presence of neurological involvement (n = 10) or not (n = 45), and counts of MES in the two were compared with each other and with normal subjects. We found MES in 16 patients (29%) with BD. The frequency was higher in patients with neurological involvement than in those without (80% vs. 17%, P < 0.001). In patients with neurological involvement there was a positive correlation in regression analysis between the prevalence of MES and disease duration (P = 0.025). There was a significantly higher prevalence of MES in BD patients than in control subjects. The frequency of MES was higher in patients with neurological involvement than in those without. TCD detection of MES may allow the recognition of subset of patients at high risk for the appearance of neurological involvement.