This study asks whether prolonged antihypertensive therapy will "cure" a substantial percent of rigorously treated hypertensive patients and whether nutritional change will add an antihypertensive effect and reduce the relapse rate. Of 584 eligible patients normotensive while receiving therapy, 496 were randomized into control and discontinued-medication groups with and without dietary intervention. At 56 weeks, 50% of those who were no longer receiving medication remained normotensive by study criteria. Randomization either to weight-loss group (mean loss of 4.5 kg [10 lb]) or to sodium-restriction group (mean reduction of 40 mEq/day) increased the likelihood of remaining without drug therapy, with an adjusted odds ratio of 2.17 for the sodium group and 3.43 for the weight group. Highest success rates were in the nonoverweight mild hypertensives with sodium restriction (78%) and the overweight mild hypertensives who were reducing their weight (72%). These data demonstrate that weight loss or sodium restriction, in hypertensives controlled for five years, more than doubles success in withdrawal of drug therapy.