< p > The distribution of heavy metal concentration in water and sediment samples from Ero River in South western, Nigeria was carried out for a period of dry and wet season. For both seasons Ni, Cd, Co were not detected in the water samples, while all metal examined were detected in the sediment samples. The concentrations of heavy metals were higher in the sediments than water sample. On the average the concentration of most the heavy metals appears higher in the dry season than wet season. The result obtained fell within the maximum allowable limit set by United State Environmental Protection Agency and World Health Organization.