The study of viral gene expression had led to the elucidation of several cellular and molecular processes operating in Eukaryotic cells. HIV is a very interesting study model as it exploits classical as well as non-conventional host pathways to accomplish efficient gene expression. As such, the viral transcripts that are generated by fully splicing of a precursor 9-kb viral mRNA associate with the classical cellular mRNP components and follow the same pathway as the host´s mRNAs. In contrast, other viral transcripts undergo partial splicing or are unspliced and therefore are expected to lack the main mRNP components being forced to exit the nucleus by an alternative pathway. In addition, viral transcripts exported through this pathway were shown to carry a trimethylated cap structure at their 5´ end, modification required for efficient gene expression but not detected to date in cellular mRNAs. In this career to produce high amount of viral proteins, HIV usurps several host proteins and/or machineries in its own benefit. The precise knowledge of all these processes is essential for the discovery and development of novel therapeutic targets for pharmaceutical intervention.