Many studies have already been undertaken on the African ichthyofauna, and the current state of ichthyologic knowledge for some African provinces, such as the Lower Guinea, is relatively well advanced. However, if some of the Lower Guinea province basins, such as the basins of the Cross, Ntem and Ogowe, have been subjected to fairly extensive studies, others like the Shiloango basin remain still poorly known. It this within this current context that we have initiated a study of the fish fauna of the Shiloango basin, which is the situated at the ichtyogeographical borderline between the Lower Guinea and Congo ichthyofaunal provinces. The Shiloango River - also known as the Tshiloango, Chiluango or Louango upstream forms the border between the Republic of Congo and the Democratic Republic of the Congo (DRC), while downstream it becomes the border between Angola (Cabinda) and the DRC. It flows into the Atlantic Ocean north of Lândana (Angola-Cabinda). Its watershed covers ±5,170 km2, and its main tributaries are the Lukula (DRC), the Fubu (DRC), and the Luali (Angola-Cabinda). A compilation of the existing information based on historical museum collections and newly made collections (2011-2013) arrives at a total of 124 species belonging to 77 genera and 34 families. With 16 species, the Cyprinidae is the most species rich family, followed by the Cichlidae and Clariidae with respectively 14 and 11 species. Fourteen species are marine, while seven other are brackish water species, following Whitfield s categorization (2007). Two species are endemic, i.e. Labeobarbus aspius (Boulenger, 1912) and Mastacembelus shiloangoensis (Vreven, 2004). The number of species currently inventoried largely exceeds the number of 57 as empirically predicted by the formula of Hugueny (1989), which seems general for Lower Guinea. In a next phase, , the Lukula (DRC), which is the largest tributary but with only 22 species known, will be sampled.