This work aims at the removal of textile dye namely methylene blue (MB) from an aqueous solution using ZnO nanoparticle loaded flexible polyurethane (PU) foam composite. ZnO nanoparticle loaded PU foams were successfully synthesized by adding ZnO nanoparticles at varying weights (0.1 g, 0.2 g, 0.3 g, 0.4 g and 0.5 g) in the foaming blend. Synthesized foam composites were characterized for bulk density and sol fraction. The cellular morphology of the foams was characterized using Scanning Electron Microscope (SEM). PU foam shows highly porous and open cell structure. Degradation of MB dye from an aqueous model pollutant was carried out using prepared foam composites under UV and solar irradiations. It has been observed that irradiation under solar source degrades MB dye in a short span of time as compared to UV irradiation. The effect of nanoparticle loading, time of irradiation and reuse of foam on MB dye degradation from synthetic waste water was effectively studied. Moreover, experimental data also exhibits first order degradation kinetics and the rate constants were found to be 0.66 h−1 under UV light and 3.07 h−1 in sunlight. © 2020, The Korean Fiber Society.