We describe the clinical features of 103 patients presenting with fixed dyston ia and report the prospective assessment and investigation of 41 of them. Most p atients were female (84%) and had a young age of onset [mean 29.7 (SD 13.1) ye a rs]. A peripheral injury preceded onset in 63%and spread of dystonia to other b ody regions occurred in 56%. After an average fol low up of 3.3 years (overal l disease duration 8.6 years), partial (19%) or complete (8%) remission had oc curred in a minority of patients. The fixed postures affected predominantly the limbs (90%), and rarely the neck/shoulder region (6%) or jaw (4%). In the pro spectively studied group, pain was present in most patients and was a major comp laint in 41%. Twenty percent of patients fulfilled criteria for Complex Regiona l Pain Syndrome (CRPS). No consistent investigational abnormalities were found a nd no patient tested (n = 25) had a mutatioin the DYT1 gene. Thirty seven perce nt of patients fulfilled classification criteria for documented or clinically es tablished psychogenic dystonia; 29%fulfilled DSM IV (Diagnostic and statistica l manual of mental disorders, 4th edition) criteria for somatization disorder, w hich was diagnosed only after examination of the primary care records in many ca ses; and 24%fulfilled both sets of criteria. Ten percent of the prospectively s tudied and 45%of the retrospectively studied patients did not have any evidence of psychogenic dystonia, and detailed investigation failed to reveal an alterna tive explanation for their clinical presentation. Detailed, semi structured neu ropsychiatric assessments in a subgroup of 26 patients with fixed dystonia and i n a control group of 20 patients with classical dystonia revealed dissociative ( 42 versus 0%, P = 0.001) and affective disorders (85 versus 50%, P = 0.01) sig nificantly more commonly in the fixed dystonia group. Medical and surgical treat ment was largely unsuccessful. However, seven patients who underwent multidiscip linary treatment, including physiotherapy and psychotherapy, experienced partial or complete remission. We conclude that fixed dystonia usually, but not always, occurs after a peripheral injury and overlaps with CRPS. Investigations are typ ically normal, but many patients fulfil strict criteria for a somatoform disorde r/psychogenic dystonia. In a proportion of patients, however, no conclusive feat ures of somatoform disorder or psychogenic disorder can be found and, in these p atients, whether this disorder is primarily neurological or psychiatric remains an open question. Whilst the prognosis is overall poor, remissions do occur, par ticularly in those patients who are willing and able to undergo multidisciplinar y treatment including physiotherapy and psychotherapy, suggesting that this type of treatment should be recommended to these patients. We describe the clinical features of 103 patients presenting with fixed dyston ia and report the prospective assessment and investigation of 41 of them. Most p atients were female (84%) and had a young age of onset [mean 29.7 (SD 13.1) ye a rs]. A peripheral injury preceded onset in 63% and spread of dystonia to other central regions occurred in 56%. After an average fol low up of 3.3 years (overal l disease duration 8.6 years), partial (19%) or complete (8%) remission had oc curred in a minority of patients. The fixed postures affected predominantly the limbs (90%), and rarely the neck / shoulder region (6%) or jaws (4%). In the pro spectively studied group , pain was present in most patients and was a major compint in 41%. Twenty percent of patients fulfilled criteria for Complex Regiona l Pain Syndrome (CRPS). No consistent investigational abnormalities were found a nd no patient tested (n = 25) had a mutatioin the DYT1 gene. Thirty seven perce nt of patients fulfilled classification cr 29% fulfilled DSM IV (Diagnostic and statistica l manual of mental disorders, 4th edition) criteria for somatization disorder, w hich was diagnosed only after examination of the primary care records in many ca ses; Ten percent of the prospectively s tudied and 45% of the retrospectively studied patients did not have any evidence of psychogenic dystonia, and detailed investigation failed to reveal an alterna tive explanation for their clinical presentation. Detailed, Semi structured neu ropsychiatric assessments in a subgroup of 26 patients with fixed dystonia and ina control group of 20 patients with classical dystonia revealed dissociative (42 versus 0%, P = 0.001) and affective disorders (85 versus 50%, P = 0.01) sig nificantly more commonly in the fixed dystonia group. Medical and surgical treatment was largely unsuccessful. However, seven patients who underwent multidiscip linary treatment, including physiotherapy and psychotherapy, experienced partial or complete remission. We conclude that fixed dystonia usually, but not always, occurs after a peripheral injury and overlaps with CRPS. Investigations are typically normal, but many patients fulfill strict criteria for a somatoform disorde r / psychogenic dystonia. In a proportion of patients, however, no conclusive feat ures of somatoform disorder or psychogenic disorder can be found and, in these p atients, whether this disorder is to neurological or psychiatric remains an open question. Whilst the prognosis is overall poor, remissions do occur, par ticularly in those patients who are willing and able to undergo multidisciplinar y treatment including physiotherapy and psychotherapy, suggesting that this type of treatment should be recommended to these patients.