Aims: To compare the short-term efficacy of treatment with a stabilization appliance compared with that of a non-occlusal, control appliance in patients with temporomandibular disorders (TMD) of mainly myogenous origin. Methods: A randomized, controlled trial was performed with 60 patients suffering from myofascial pain. Patients were randomly assigned to a treatment or a control group. The treatment group was treated by means of a stabilization appliance and the control group by means of a non-occlusal appliance. Symptoms and signs were registered before and after 10 weeks of treatment. Results: Improvement of overall subjective symptoms was reported in both groups, but significantly more often in the treatment group than in the control group (P = .000). The prevalence of daily or constant pain showed a significant reduction in the treatment group (P = .028) compared with the control group. There was a significant decrease in the number of tender masticatory muscles in the treatment group (P = .018) compared with the control group. Conclusion: The results of this short-term evaluation suggest that the stabilization appliance is more effective in alleviating symptoms and signs in patients with TMD of mainly myogenous origin than a control, non-occlusal appliance. The stabilization appliance can therefore be recommended for the therapy of these patients.