study the clinical characteristics of 2952 patients with epilepsy who had received drug treatment from the neurology outpatient clinics of eight major hospitals in Hong Kong Methods Retrospective review of outpatient records Results 1601 (54 3%) males and 1351 (45 7%) females with a median age of 35 8 years (range, 10-94 8) were studied Seizure types included generalized tonic clonic in 80 7% of patients, complex partial in 28 3%, simple partial in 14 4%, atypical absence in 2 6% and myoclonic in 1 4%, and 30 4% of patients had more than one seizure type EEG, CT brain, MRI brain and neuropsychological evaluation were obtained in 81 2%, 61 7%, 17 0% and 2 2% of patients, respectively The etiology of epilepsy was cryptogenic in 59 9%, symptomatic in 35 1% and idiopathic in 3 9%; the commonest were intracranial infection, cerebral vascular disease, cranial trauma and perinatal insult Phenytoin, carbamazepine and valproate were the most frequently used drugs and 25 9% of patients were taking more than two drugs 48 3% of patients had active seizures in the past six months and 26 4% were considered to have unsatisfactory control of their epilepsy Medical refractoriness of epilepsy was associated with a history of perinatal insult, intracranial infection, congenital brain malformation, intracranial neoplasm, cerebral vascular disease, hippocampal sclerosis, mental retardation and a history of status epilepticus ( P <0 05) Conclusion In this local cohort of adult patients with epilepsy under specialist care, there were a considerable number of patients falling into the category of cryptogenic epilepsy Risk factors associated with medical refractoriness are similar to previous studies study the clinical characteristics of 2952 patients with epilepsy who had received drug treatment from the neurology outpatient clinics of eight major hospitals in Hong Kong Methods Retrospective review of outpatient records Results 1601 (54 3%) males and 1351 (45 7%) females with a median age of 35 8 years (range, 10-94 8) were studied Seizure types included generalized tonic clonic in 80 7% of patients, complex partial in 28 3%, simple partial in 14 4%, atypical absence in 2 6% and myoclonic in 1 4%, and 30 4% of patients had more than one seizure type EEG, CT brain, MRI brain and neuropsychological evaluation were 81%, 61 7%, 17 0% and 2 2% of patients, respectively The etiology of epilepsy was cryptogenic in 59 9%, symptomatic in 35 1% and idiopathic in 3 9%; the commonest were intracranial infection, cerebral vascular disease, cranial trauma and perinatal insult Phenytoin, carbamazepine and valproate were the most frequently used drugs a nd 25 9% of patients were taking more than two drugs 48 3% of patients had active seizures in the past six months and 26 4% were considered to have unsatisfactory control of their epilepsy Medical refractoriness of epilepsy was associated with a history of perinatal insult , intracranial infection, congenital brain malformation, intracranial neoplasm, cerebral vascular disease, hippocampal sclerosis, mental retardation and a history of status epilepticus (P <0 05) Conclusion In this local cohort of adult patients with epilepsy under specialist care, there were a considerable number of patients falling into the category of cryptogenic epilepsy Risk factors associated with medical refractoriness are similar to previous studies