A current view of HIV assembly in macrophages. The viral genomic RNA transcribed in the nucleus is exported to the cytoplasm. The transmembrane envelope (Env) protein is produced in the endoplasmic reticulum and transits through the Golgi apparatus while Gag is synthesized on free cytosolic ribosomes. Both Env and the Gag precursors are targeted to the assembly site through unidentified pathways. The sites of Gag/Env interaction, Gag multimerization and binding to viral genomic RNA remain elusive as well. The main cellular factors suspected to play a role in these trafficking events are indicated; nevertheless most of the time their roles have still to be established in macrophages. The assembly process requires the hijacking of the cellular ESCRT machinery and occurs on cholesterol- and tetraspanin-enriched membrane microdomains. The assembly compartment can be connected at least transiently to the plasma membrane through thin microchannels that do not allow virion passage. The limiting membrane of the viral assembly compartment as well as the microchannels often exhibit thick molecular coats of which the composition remains obscure. See text for details.