The plasma membrane, late secretory pathway and endosomal compartments contain detergent-insoluble raft microdomains that are enriched in sphingolipids and cholesterol. Rafts are currently an intensively studied topic of cell biology, and raft involvement has been implicated in numerous cellular processes. A number of recent reports have localized structural proteins of several enveloped viruses to rafts, thus raising the possibility that rafts also play a role in the assembly and budding of viruses, but what exactly that role might be is still unknown.