Two groups of 20 subjects with elevated muscle tension levels were provided with either contingent (Group 1) or false (Group 2) EMG feedback from the frontalis muscle. Each group received 8 sessions of identical length. Performance of the 2 groups over the final training session was compared. Group 1 showed a marked decrease in frontalis EMG levels over Session 8 whereas Group 2 showed no change in frontalis activity. However, both groups showed a significant increase in reported feelings of relaxation with no difference between groups. To investigate the possibility that subjects attaining very low frontalis levels might show a more marked subjective response, 10 subjects from Group 1 who showed the most marked decrease in EMG activity were compared with the 10 subjects from Group 2 who showed the least decrease. Although both showed an increase in mental relaxation, there was no difference between the groups.