We examined the occurrence of posttraumatic movement disorders after moderate or mild head injury with a three-level follow-up study including questionnaires, telephone interviews, and personal examinations 4-6 years after the trauma (mean 5.2 years). Sixteen of 158 patients (10.1%) for whom a detailed follow-up was available had developed movement disorders most probably related to craniocerebral trauma. The most frequent finding was a low-amplitude postural/intention tremor that appeared to resemble enhanced physiological or essential tremor. Twelve patients reported transient tremor, two patients had persistent tremor, one patient had transient tremor and persistent hyperekplexia, and another patient had mild persistent cervical myoclonic twitches. Overall, the movement disorder was transient in 12 patients (7.6%) and persisted in only 4 patients (2.6%). These movement disorders were not disabling and did not require medical therapy. Taking into account possible bias by selection of the sample group, the frequency of movement disorders secondary to moderate or mild head trauma might be lower than 10.1%. Posttraumatic movement disorders occurred significantly more often in the group of patients with Glasgow Coma Scores between 9 and 14 than in those with a score of 15. Severe movement disorders such as low-frequency kinetic tremor or hemidystonia were not identified in this survey.