The effect of dietary modification on continued blood pressure control after discontinuation of antihypertensive therapy has been studied. Participants who had been treated for 5 years in the Hypertension Detection and Follow-up Program were enrolled and randomly assigned to continue medication, discontinue medication with no dietary intervention, discontinue medication and reduce weight, discontinue medication and reduce sodium groups. Relapse of hypertension was slow, even without dietary modification. Both weight loss and sodium restriction slowed relapse. The severity of the hypertension and the number of drugs required for hypertension control had a marked effect on the rate of relapse. Relapse was slowest in the participants who had attained the lowest blood pressure on therapy.