Aggregation of misfolded proteins and progressive polymerization of otherwise soluble proteins is a common hallmark of a wide range of highly debilitating and increasingly prevalent diseases, including amyotrophic lateral sclerosis, cerebral amyloid angiopathy, type II diabetes and Parkinson's, Huntington's and Alzheimer's diseases. There is a growing interest in creating imaging agents to detect such aggregates in various imaging modalities, including PET, SPECT and MRI. We present here an overview of recent efforts from the perspective of early diagnosis of amyloid diseases, with a major focus on Aβ detection and metal complexes bearing PiB units.