Abstract In Pr 2− x Ce x CuO 4− δ compounds with x = 0.15, 0.18, we observed superconductivity below about 20 K. We measured magnetic hysteresis at 5 K in fields of 0.01–1.1 T. Above 0.5 T, the single-ion paramagnetism of Pr(3+) overwhelms the superconductivity. After correction, the superconductive M-H hysteresis loop shows a pinched-neck shape, resembling that found in BiPbSbCaSrCuO. This shape is attributed to dynamic flux-depinning effects. Time dependence of both the Meissner effect after zero-field cooling and the remanence after field cooling was studied in a 0.01 - T field. It can be described best by an empirical relationship M(t) − M(o)t − α , proving the failure of a simple thermally activated flux-creep model. One can interpret this behavior by using a spinglass model in the framework of hierarchically constrained dynamics.