BACKGROUND: Freezing of gait is a common cause of disability and falls in patients with Parkinson's disease. We studied brain functional connectivity, by means of resting-state functional magnetic resonance imaging, in patients with Parkinson's disease and freezing of gait. METHODS: Resting-state functional magnetic resonance imaging at 3 T was collected in 29 patients with Parkinson's disease, of whom 16 presented with freezing of gait as determined by a validated freezing of gait questionnaire, and 15 matched healthy controls. Single-subject and group-level independent component analysis was used to identify the main resting-state networks differing between Parkinson's disease patients with and without freezing of gait. Statistical analysis was performed using BrainVoyager QX. RESULTS: Between-group differences in resting-state networks revealed that patients with freezing of gait exhibit significantly reduced functional connectivity within both "executive-attention" (in the right middle frontal gyrus and in the angular gyrus) and visual networks (in the right occipito-temporal gyrus) [p