Pseudomonas aeruginosa CSU, a nongenetically engineered bacterial strain previously shown to bind dissolved hexavalent uranium (as UO22+ and/or its cationic hydroxy complexes), shows promise as the basis of an immobilized‐cell process for removal of dissolved uranium from contaminated wastewaters. A number of polymeric materials, including calcium alginate, polyacrylamide, polysulfone, and polyurethane, were evaluated as possible immobilization matrices for lyophilized biomass of P. aeruginosa CSU. Polyurethane‐based materials such as hydrogel were identified as superior candidates for biomass immobilization. A novel polyurethane gel‐bead fabrication technique was developed and successfully demonstrated at pilot‐plant scale for producing mass quantities of spherical, uniform‐size beads. The immobilized bacterial biomass was evaluated via the measurement of sorption isotherms and dynamics within a batch, stirred‐tank reactor; and loading and elution behavior within a continuous, upflow, packed‐bed columnar reactor. Sorption equilibrium and dynamics in a batch stirred tank were modeled with a pore‐diffusion mass transfer model, by which a pore‐diffusion coefficient was determined to be approximately 2.0 × 10−6 cm2/s for uranyl ion transport through the polyurethane gel matrix. The biosorbent beads were regenerable with dilute (0.01–0.1 M) sodium carbonate solutions. Preliminary column breakthrough‐elution studies indicated that P. aeruginosa CSU biomass immobilized within polyurethane gel beads was effective for removal of uranium from low‐concentration, acidic wastewaters.