The haemoglobin concentration of nine cohabiting teleosts of Hor al-Hammar marsh, Basrah, was carried out. The mean values (g/100 ml) were ranged from 3.2 for Alburnus sellal to 9.912 for Parasilurus triostegus. The taxononomic consideration of haemoglobin concentration appeared of a little value among the different members of the family Cyprinidae. The mean haemoglobin concentration for Barbus xanthopterus, B. sharpeyi and B. grypus were less than those taken from the same species in other Iraqi inland waters. Possible factors that cause a variation in the haemoglobin concentration in fishes were discussed.