It has been known for some time that HIV‐1 virions contain cellular proteins in addition to proteins encoded by the viral genome. Recent studies have vastly increased the number of host proteins detected in HIV‐1. This review summarises the current findings on several cellular proteins present in these virions, including some functional studies on their potential roles in the viral replication cycle and pathogenesis. Because retroviruses require extensive assistance from host proteins and pathways, the data from biochemical characterisations of HIV‐1 serve as an important starting point for understanding the role of cellular proteins that act in or influence the biology of HIV‐1. Additionally, a better understanding of the interactions between cellular proteins and viral components might provide more targets for anti‐HIV therapeutic intervention and provide for a better understanding of how HIV‐1 alters the immune system. The extensive study of HIV‐1 has already brought new insights to the fields of immunology and vaccine science. In the same way, knowledge of viral‐‐cellular protein interactions might assist our understanding of important cellular pathways. Copyright © 2008 John Wiley & Sons, Ltd.