Ten patients, diagnosed as suffering acute myocardial infarction were allocated to an Experimental (behavioural counselling with relaxation training) group, or a Control (waiting list) group. Measures of electromyogram activity, covert and self-rated anxiety, serum enzymes, length of illness and outcome were made. Experimental subjects had 12 weekly sessions of counselling on a variety of topics relating to psychological adaptation to the illness, plus relaxation training. The results show a significant reduction in muscle tension in experimental subjects after training. Significant changes were also found respecting covert anxiety. Self-rated anxiety and SGOT levels were related. More experimental than control subjects returned to work.