The aim of this study was to evaluate the therapeutic effect of occlusal adjustment on symptoms and signs of craniomandibular disorders (CMD), including headaches, after 3 and 6 months. Fifty patients were selected and randomly assigned to a treatment (T) or a control (C) group. All patients in the treatment group were subjected to occlusal adjustment, whereas the controls were comforted only. Pre- and post-treatment assessment of subjective symptoms and clinical signs was made by a dentist not performing the occlusal adjustment. There was significant improvement in overall subjective symptoms within the T group at the 3- and 6-month follow-up visits, but a statistically significant difference between groups was found at the 3-month follow-up only. With regard to changes in frequency of facial pain a significant deterioration was reported within the C group, which resulted in a significant difference between groups at the 6-month follow-up. No other significant differences were found within or between groups at the follow-ups with regard to the variables investigated. In conclusion, the results from this study show that occlusal adjustment is a treatment modality with a statistically significant short-term effect on symptoms of CMD of muscular origin and superior to counseling.