Brain amyloid imaging is becoming an essential tool for the pre-mortem evaluation of Alzheimer's disease (AD). This study explores the pattern of 11C-PiB retention in a subject with Worster-Drought syndrome (WDS). A 55 year-old male carrier of the WDS gene mutation with mild signs of ataxia and subtle cognitive impairment underwent MRI and 11C-PiB-PET studies.Brain PiB regional distribution was compared to those from cohorts of healthy controls and AD patients. While no significant cortical 11C-PiB retention was present, a high degree of cerebellar 11C-PiB retention was observed in a genetically confirmed carrier of the WDS gene. We speculate that the sparsity of ABri plaques in the neocortex together with its high deposition in the cerebellum, might explain the observed pattern of 11C-PiB retention.