OBJECTIVE: Combined hyperative dysfunction syndrome (HDS) defined as the combination of HDSs such as trigeminal neuralgia (TN), hemifacial spasm (HFS) and glossopharyngeal neuralgia (GPN), which may or may not occur simultaneously on one or both sides. We reviewed patients with combined HDS and demonstrated their demographic characteristics by comparing them with those of patients with a single HDS. METHODS: Between October 1994 and February 2006, we retrospectively studied a series of 1,720 patients who suffered from HDS and found 51 patients with combined HDSs. We analyzed several independent variables in order to evaluate the prevalence and etiologic factors of combined HDS. RESULTS: The combined HDS group accounted for 51 of 1,720 (2.97%) patients with HDS; 27 cases of bilateral HFS, 10 cases of bilateral TN and 14 cases of HFS with TN. Their mean age was 52.1 years (range, 26-79 years). There were 5 men and 46 women. Seven patients had synchronous and 44 patients metachronous onset of HDSs. By comparison of combined and single HDS groups, we found that age and hypertension were closely associated with the prevalence of combined HDS (p < 0.05). CONCLUSION: This study revealed that combined HDS was very rare. Hypertension and age might be the most important causative factors to evoke combined HDS.