Clinical material is presented from the analyses of two patients who as small children had had surgical operations. In each case pre-existing Oedipal anxiety and guilt about masturbation led to the operation having a traumatic effect, producing phobic symptoms and character defences. Both patients responded unconsciously to competitive situations in adult life as though to the threat of an operation, and the repetitive nature of this reaction constituted a problem. Therapeutic progress in each case was the result of uncovering repressed emotions associated with the operation and interpreting the way in which the ego-defences used to deal with current problems were a repetition of those used to deal with the infantile trauma.