The recycling constant Rc=D/2σkr of the wall (D=diffusivity, 2σkr=surface release rate constant of hydrogen) is an essential parameter for the understanding of the hydrogen recycling phenomena in fusion devices. It has been measured insitu in TEXTOR, using the wall pump and release effect. The method is described and data are presented in the temperature range of 150–300 °C for surfaces prepared by different conditioning techniques. The values are compared to available literature data from other tokamaks and from laboratory experiments.