Randomized clinical trials of amitriptyline will require data from pilot studies to be used for sample size estimates, but such data are lacking. This study investigated the 6-week and 1-year effectiveness of low dose amitriptyline (10-30 mg) for the treatment of patients with chronic temporomandibular disorder (TMD) pain. Based on clinical examination, patients were divided into two groups: myofascial and mixed (myofascial and temporomandibular joint disorders). Baseline pain was assessed by a Visual Analogue Scale (VAS) for pain intensity and by the McGill Pain Questionnaire (MPQ). Depression was assessed by the Beck Depression Inventory (BDI) short form. Patient assessment of global treatment effectiveness was obtained after 6 weeks and 1 year of treatment by using a five-point ordinal scale: (1) worse, (2) unchanged, (3) minimally improved, (4) moderately improved, (5) markedly improved. The results showed a significant reduction for all pain scores after 6 weeks and 1 year post-treatment. The depression scores changed in depressed but not in non-depressed patients. Global treatment effectiveness showed significant improvement 6 weeks and 1 year post-treatment. However, pain and global treatment effectiveness were less improved at 1 year than at 6 weeks.