This study aims to separate various forms of inorganic phosphorus as well as determining the total phosphorus in river sediments in the city of Ibadan. Inorganic phosphorus was fractionated using appropriate extractants to obtain: loosely bound, Al–P, Fe–P, reductant and Ca–P. Results for total phosphorus ranged from 379 to 1156 µg P g-1. Inorganic phosphorus was found to be the major constituent of the total extractable phosphorus in all the rivers surveyed. Ca–P was the dominant inorganic form in 18 of the 27 samples analysed. Al–P was identified as the minor constituent of inorganic phosphorus in all samples and was identified as the least significant non-apatitic form in the sediment samples. The Bray-P1 available phosphorus ranged from 11 to 100 µg P g-1. The results of total phosphorus analysis in the sediments are indicative of the high pollution of some of the rivers. Speciation results reveal that most of the inorganic phosphorus is fixed in the apatitic form.