This chapter attempts reciprocal inhibition using muscular relaxation as the response antagonistic to generalized excitement. Developed for treating neurotics, reciprocal inhibition is not considered useful for psychotic conditions. Except for phobias or enuresis there has been little systematic investigation of reciprocal inhibition techniques with children. It appears that reciprocal inhibition is most effective with adult neurotics, less so with nonpsychotic children, and of no use with psychotic children. The criteria of relaxation were: five consecutive sessions in which the child was cooperative, quiet, and visibly "loosening" on instruction. The most interesting finding was that, in addition to the decrease of excitement response during relaxation training, there was an unpredicted and marked decrement of the generalized excitement response throughout the whole day. The autistic children learned to perform muscular relaxation in a small group situation and gave behavioral indications that the activities were reinforcing for them.