We present a clinical case report of posterior cortical atrophy (PCA) due to Alzheimer’s disease. PCA is a clinico-radiological syndrome, characterized by progressive visuospatial and perceptual deficits and atrophy of posterior brain regions. PCA as well as other atypical variants of AD have a relatively young onset age (prior to the age of 65) and memory is usually preserved at the earlier stages of the disease. Therefore, a neurodegenerative disease is often not suspected and diagnosis is delayed. Our case report illustrates that the diagnosis of PCA should be considered in patients with progressive visual dysfunction of an unknown etiology. Amyloid diagnostics can be used to confirm the clinical diagnosis of Alzheimer’s disease, especially in cases with atypical clinical presentation.