BACKGROUND AND PURPOSE: Inflammation plays an important role in the initiation and progression of atherosclerosis but the contribution of neutrophils to this process is unclear. Asymptomatic cerebral microembolization can be detected by transcranial Doppler (TCD) and has been associated with increased risk of early stroke recurrence in patients with recently symptomatic carotid stenosis. In the present study, we sought to determine whether spontaneous microembolization was associated with neutrophil count in patients with recently symptomatic carotid stenosis. METHODS: We continuously monitored Transcranial Doppler (TCD) spectra of middle cerebral artery blood flow ipsilateral to recently symptomatic carotid artery stenosis in 60 consecutive patients. Microembolic signals (MES) were diagnosed by experienced observers blinded to leukocyte count and high-sensitive C-reactive protein (hs-CRP) level measurement. RESULTS: We found MES in 20 (33.3%) patients. Microembolization was associated with higher neutrophil counts (p=0.003). Differences in monocyte count and lymphocyte count between patients with MES and patients without MES were not statistically significant. Microembolization remained strongly associated with neutrophil count in multivariable analysis (p=0.003) whereas the association with hs-CRP was not significant. CONCLUSIONS: Neutrophil count was associated with microembolization in patients with recently symptomatic carotid artery stenosis. Our findings suggest that neutrophils may play a role in the pathogenesis of stroke related to carotid atherosclerosis.