A process for producing foamed thermoplastic polyurethane particles comprises the steps of a) melting a thermoplastic polyurethane in a first extruder (E1), b) injecting a gaseous blowing agent in a second extruder (E2), c) impregnating the gaseous blowing agent homogeneously into the thermoplastic polyurethane melt in a third extruder (E3), d) extruding the impregnated thermoplastic polyurethane melt through a die plate and granulating the melt in an underwater granulation device under temperature and pressure conditions to form foamed thermoplastic polyurethane particles.