We have reviewed the literature on the effect of withdrawal of antihypertensive therapy on return to hypertension. We also present our data from 83 patients in whom a 12-month follow-up period showed that 28% required re-institution of therapy within 10 weeks of withdrawal of medication, over half by 20 weeks, but a significant proportion (28%) stayed normotensive off therapy for a year. All patients had met the criteria for resumption of antihypertensive medication after 2 years of therapy. We also demonstrated predictive effects of left ventricular hypertrophy and duration of therapy on rate of redevelopment of hypertension. Our study raises the possibility that echocardiography may indicate the likelihood of a rapid return to hypertension when drug therapy is ceased.