This study was designed to compare the clinical effectiveness of EMG biofeedback and progressive relaxation training in the treatment of muscle tension headache. These procedures also were compared with a treatment-element control group. Results from this study indicated that EMG biofeedback, progressive relaxation, and the control procedures all led to significant improvements across sessions on EMG and most self-report measures. There was little evidence that either treatment technique was superior to the other or to the control procedures. Although in most cases there were rather large numerical differences between groups, these differences generally were not statistically significant. Analysis of correlations between EMG and self-report data revealed a pattern of variable but generally nonsignificant relationships. However, for the biofeedback and progressive relaxation groups, there were a number of highly significant correlations. The pattern of correlations suggested that the relationship between EMG tension and subjective headache pain may be better predicted by something other than a strict linear model.