Imaging techniques for in vivo visualization of cerebral amyloid using positron emission tomography (PET) have been tested in clinical trails over the past 5 years. Based on a selected overview of the literature including our own studies the various radiopharmaceuticals are presented and the current status of research on the validity of amyloid PET imaging as well as its suitability for early and differential diagnosis of Alzheimer's disease (AD) are described. The findings available up to now support the validity of amyloid PET imaging and suggest a possible benefit in differential diagnosis. However, there are as yet no studies with large sample sizes. The possible use for the early diagnosis of AD should be viewed critically, particularly due to the lack of treatment options.