Backgrounds: The diagnosis of Tourette syndrome may be overlooked in patients with severe psychopathologic disorder but mild motor manifestations of Tourette syndrome. Objective: To describe 4 patients with long-lasting general psychopathologic disorder and previously unrecognized mild motor and phonic tics exacerbated during adulthood by the onset of tremor; all of the patients had been referred for the evaluation of psychogenic tremor. Subjects: Four adult patients, with previous psychiatric diagnoses of depression (2 cases), generalized anxiety disorder (3 cases), malingering (1 case), and conversion disorder (3 cases). Methods: Single case studies. Results: Clinical interviews disclosed that the 4 patients had positive family histories of Tourette syndrome, and all had mild motor and phonic tics that had started before the age of 18 years. On neurologic examination, 2 patients had bilateral postural tremor of the hands that varied in frequency, rhythmicity, and amplitude, and the other 2 had resting tremor mimicking parkinsonism. All 4 patients described involuntary somatic sensations of the affected limbs, which they attempted to alleviate by executing movements. No consistent positive placebo response was observed, but in all patients tremoric movements improved with haloperidol. Conclusions: These cases illustrate an unusual movement disorder (tremor as a 'tic equivalent') in adults with Tourette syndrome and emphasize that cases of the syndrome with mild tics often go unrecognized, precluding adequate treatment.