In this study, highly effective removal of cesium (Cs) from aquatic medium was achieved by developing a hybrid material by infusing ferric hexacyanoferrate(II) (PB) in calcium alginate in the form of beads. The PB–Ca–Alg beads showed high removal efficiency (>90%) for both ¹³⁷Cs and stable Cs from different contaminated aquatic medium. Langmuir isotherm is followed for the sorption of the Cs using PB–Ca–Alg beads. The maximum sorption capacity of Cs using the beads was calculated to be 55.04 mg g^-1. The uptake was following the pseudo second order rate law for the beads as evident from the kinetic study.