Kinesin superfamily proteins (KIFs) are key players or 'hub' proteins in the intracellular transport system, which is essential for cellular function and morphology. The KIF superfamily is also the first large protein family in mammals whose constituents have been completely identified and confirmed both in silico and in vivo. Numerous studies have revealed the structures and functions of individual family members; however, the relationships between members or a perspective of the whole superfamily structure until recently remained elusive. Here, we present a comprehensive summary based on a large, systematic phylogenetic analysis of the kinesin superfamily. All available sequences in public databases, including genomic information from all model organisms, were analyzed to yield the most complete phylogenetic kinesin tree thus far, comprising 14 families. This comprehensive classification builds on the recently proposed standardized nomenclature for kinesins and allows systematic analysis of the structural and functional relationships within the kinesin superfamily.