Self-stimulatory responses of four retarded/autistic children were reduced using brief immobilization. A reversal design was employed such that immobilization was systematically applied and withdrawn to one category of responses while the effects of collateral responses were also assessed. In three cases, the suppressive effects of immobilization generalized to collateral responses of similar topography, but in one of these cases there were undesirable side effects. In the fourth case, where generalized suppression did not occur, the collateral responses were of dissimilar topography from the target response. Results indicated that immobilization is an effective procedure for reducing self-stimulatory responding and that the effects may generalize to other responses under some circumstances. In the present study, the emergence of an incompatible response appeared to be responsible for most of the response generalization effects.