A synthesis of the knowledge about the Lusitanian Basin is presented here, focusing on its stratigraphic record, sedimentary infill, evolution, and petroleum systems. Petroleum system elements are characterized, including Palaeozoic and Mesozoic source rocks, siliciclastic and carbonate reservoirs, and Mesozoic and Tertiary seals and traps. Related processes, such as organic matter maturation and hydrocarbons migration are also discussed. The characteristics of these elements and processes are analysed and implications for deep offshore exploration are discussed.