This is a case report which illustrates the importance of the analysis of posture in psycho-analytical therapy. The author shows how visual observation and timely interpretation of the postural activity facilitates verbal communication between patient and analyst. The concept of 'acting in' is used to describe a middle phase in a genetic continuum in which acting out is at one end—'acting in' lying in between and verbalizing and remembering without action at the other end. 'Acting in' is a compromise between id impulse and ego defence. Postural acts or other kinds of blocked body movements on the couch may be thought of as 'acting in'. In is acting within the analysis.