The TRIM/RBCC proteins belong to a family whom members are involved in a variety of cellular processes such as apoptosis and cell cycle regulation. These proteins are defined by the presence of a tripartite motif composed of three zinc-binding domains, a RING finger, one or two B-box motifs, a coiled-coil region and a highly variable C-terminal region. Interestingly, the preserved order of the tripartite motif from the N- to the C-terminal end of the protein and the highly conserved overall architecture of this motif throughout evolution suggest that common biochemical functions may underline their assorted cellular roles. Here we present the structure and the proposed function of each TRIM domain including the highly variable C-terminal domain.