ABSTRACT: This research aimed at determination of the levels and speciation of arsenic (As) and iron (Fe) in water and sediments from Hunki Ox-bow Lake in Awe L.G.A of Nasarawa State, using Atomic Absorption Spectrophotometer (AAS), during the dry and wet seasons. The mean concentration of As in water and whole (raw) sediment samples of both dry and wet seasons was lower than that of Fe. For both seasons, the baseline levels of As and Fe in water samples were 1.674 mg/L and 4.551 mg/L, respectively, which revealed that As content in water was higher than the WHO Guidelines for Drinking Water Quality. The baseline levels of As and Fe in sediment samples (mg/kg) were as follows: As (93.935) and Fe (264.429) which showed that As was higher than both Interim Sediment Quality Guidelines – Low of 20 mg/kg and Interim Sediment Quality Guidelines – High of 70 mg/kg. This study revealed that: concentration of As and Fe from sediments and water were generally higher in wet season than dry season, levels of As and Fe from sediments were higher than that of water, concentrations of As and Fe were more of natural than anthropogenic sources and the ecological risk indices evaluated evidenced As to be of greater ecological risk than Fe.