We studied the incidence and results of treatment of secondary hypertension in Yeungnam University Hospital. Nineteen hundred fifty patients with hypertension were included from march 1990 to march 1994. We analysed the prevalence of secondary hypertension and results of treatment. The incidence of secondary hypertension in Yeungnam University Hospital was six percent. The most common underlying causes of secondary hypertension was renal parenchymal disease. Patients with three forms of potentially reversible secondary hypertension, namely, renovascular hypertension, endocrine disease, exogenous hormone, were assed to determine whether surgery or withdrawal of the exogenous hormane had led to an improvement in blood pressure control. The incidence of secondary hypertension in Yeungnam University Hospital was low(6%), but some of these are curable. Thus it is very inportant that evaluate the secondary hypertension.