Ubiquitination is one of the posttranslational modifications that regulates a number of intracellular events including signal transduction, protein quality control, transcription, cell cycle, apoptosis and development. The ubiquitin system functions as a garbage machine to degrade target proteins and as a regulator for several signalling pathways. Biochemical reaction of ubiquitination requires several enzymes including E1, E2 and E3, and E3 ubiquitin ligases play roles as receptors for recognizing target proteins. Most of the tripartite motif (TRIM) proteins are E3 ubiquitin ligases. Recent studies have shown that some TRIM proteins function as important regulators for a variety of diseases including cancer, inflammatory diseases, infectious diseases, neuropsychiatric disorders, chromosomal abnormalities and developmental diseases. In this review, we summarize the involvement of TRIM proteins in the aetiology of various diseases.