Knowledge of monogeneans is still incomplete in Africa and the present numbers of these parasites on/in fishes in the region are likely an underestimate, as a relatively few hosts have been examined. Today, more than twenty years since the last compilation (see Khalil and Polling, 1997), a total of 455 species of polyonchoineans (32 genera in three families) and seven species of oligonchoineans (three genera in two families) have been described. Given the high diversity of freshwater fish species in Africa (approximately 2950 spp.), monogenean species are therefore still poorly known. At the family level, the Dactylogyridae are represented currently by the greatest number of species (402 spp.) belonging to 26 genera: Afrocleidodiscus (3), Ancyrocephalus (s.l.) (4), Annulotrema (46), Archidiplectanum (1), Bagrobdella (3), Birgiellus (3), Bouixella (10), Characidotrema (10), Cichlidogyrus (103), Dactylogyrus (100), Dogielius (21), Enterogyrus (8), Eutrianchoratus (5), Heteronchocleidus (5), Heterotesia (1), Insulacleidus (3), Nanotrema (2), Onchobdella (8), Paraquadriacanthus (1), Protoancylodiscoides (6), Quadriacanthus (30), Schilbetrema (14), Schilbetrematoides (2), Scutogyrus (7), Synodontella (5), and Urogyrus (1). Only a single species of diplectanids, Diplectanum lacustre, has been reported from Lates niloticus. The viviparous gyrodactylids are the second largest family, with 52 species attributed to five genera, i.e. Afrogyrodactylus (4), Diplogyrodactylus (1), Gyrodactylus (37), Macrogyrodactylus (9), and Mormyrogyrodactylus (1). The only representatives of the Oligonchoinea are six species belonging to Paradiplozoon (5), Afrodiplozoon (1) (Diplozoidae) and one species of Heterobothrium (Diclidophoridae).