Introduction: The aberrant or misfolded forms of the prion protein have been described as the causative agents of rare transmissible spongiform encephalopathies. In addition, proteins associated with frequently occurring neurodegenerative disorders, such as Alzheimer's and Parkinson's, are shown to share prion-like properties and to spread the disease in the brain.Areas covered: Interest in the prion phenomenon has crystallized in a series of computational methods aimed at uncovering prion-like proteins at the proteome level. These programs rely on the identification of sequence signatures similar to those of yeast prions, whose structural conversion is driven by specific domains enriched in glutamine/asparagine residues. A myriad of prion-like candidates, similar to those in yeast, are predicted to exist in organisms across all kingdoms of life. We review here the role of prions, prionoids and prion-like proteins in health and disease, with a special focus on the algorithms and databases developed for their prediction and classification.Expert commentary: Computational approaches provide novel insights into prion-like protein functions, their regulation and their role in disease.