The aims of this study were to investigate the brain network connectivity alterations of intractable unilateral mesial temporal lobe epilepsy (MILE) with cognitive dysfunction before and after anterior temporal lobectomy (ATL) using resting-state functional magnetic resonance imaging (rs-fMRI) study and to further observe the correlation between the brain network connectivity with cognitive performance. Fourteen patients with unilateral left MTLE before and after ATL were compared with thirty healthy controls (HCs) on functional connectivity (FC) between resting-state networks (RSNs). The correlation between the neuropsychological tests of patients and abnormal FC was further investigated. When compared with the HCs, patients before surgery showed significantly changed IC between special RSNs. No difference of IC was found between each RSN when patients were compared with the HCs after surgery. Compared with patients before surgery, patients after surgery showed significantly decreased FC between RSNs. Abnormal FC between RSNs significantly correlated with Montreal Cognitive Assessment (MoCA) scores. Our study suggested that dynamic alterations of RSN after An in unilateral MILE may be closely related with seizure generating. However, unchanged FC between RSN before and after An may be closely related with cognitive performance. The present findings may help us understand the feature of brain network alterations in patients with left MTLE who became seizure-free following ATL. (C) 2018 Elsevier Inc. All rights reserved.