6-SUBSTITUTED 3-CARBETHOXYHYDRAZINOPYRIDAZINES OF THE GENERAL FORMULA: ##STR1## wherein R.sub.1 and R.sub.2, which may be the same or different, represent a lower alkyl group containing from 1 to 6 carbon atoms, an allyl group, a 2-hydroxyethyl group or a 2-hydroxypropyl group, as well as the pharmaceutically acceptable salts thereof. Also a method of preparation. These compounds have anti-hypertensive activity.