Undoped multiple quantum well (MQW) samples grown by the molecular beam epitaxy method were irradiated by 5.15 MeV energy alpha particles. A strong influence of irradiation on the photoluminescence (PL) intensity was observed in these nearly intrinsic samples: the PL intensity at liquid nitrogen and room temperatures decreased by more than two orders of magnitude at alpha particle fluence of 10(11) cm(-2). The dependence of the PL intensity on irradiation dose is described by a rate equation model that takes into account the generation of nonradiative point centers in barriers and wells of the MQW structure during irradiation.