1. The use of large doses of oxprenolol and a diuretic had a stronger antihypertensive action than the diuretic alone.
2. The combined use of oxprenolol and a diuretic had a strong antihypertensive effect in a majority of the mild, moderate and severe hypertensive patients studied.
3. Oxprenolol caused strikingly few side effects, and it especially did not cause cardiac insufficiency when used in combination with a diuretic.
4. When dihydralazine was added to oxprenolol, it did not cause a further significant fall in arterial pressure, except in a few impressive instances.