Background: Benign tremulous parkinsonism has never been precisely defined nor has the long-term course been studied. Objective: To report the clinical features and longitudinal course of patients with benign tremulous parkinsonism encountered in our movement disorders practice. Design: Computer search of medical records database. Setting: Mayo Clinic, Rochester, Minn. Patients: Of 116 patients identified, 16 (10 male and 6 female) had at least an 8-year history of this disease, had been examined by a senior movement disorders specialist, and had ultimately been diagnosed as having benign tremulous parkinsonism after an initial diagnosis of Parkinson disease (PD). Interventions: None. Main Outcome Measures: Age at onset of disease, response to levodopa therapy, tremor characteristics, and family history. Results: Mean disease duration was 11 years (range, 8-25 years) at last follow-up. Mean age at onset, 58.5 years, was younger than in most PD series, and most patients had a poor levodopa response (although levodopa trials were inadequate in some). A moderate to marked postural tremor was noted in 13 of the 16 patients, including 6 with a kinetic tremor. A family history of PD and/or tremor was reported in 10 (63%) of our patients. Three patients required thalamic deep brain surgery to treat their tremor. Conclusions: Benign tremulous parkinsonism may be a distinct clinical entity characterized by tremor predominance plus minimal progression of other aspects of parkinsonism. The tremor is often not very responsive to levodopa therapy. In this series, most patients had immediate family members with a diagnosis of tremor or PD.