THE PRESENT INVENTION IS CONCERNED WITH VASOCONSTRICIVE [(BENZODIOXAN, BENZOFURAN OR BENZOPYRAN)ALKYLAMINO]ALKYL SUBSTITUTED GUANIDINES HAVING THE FORMULA(FORMULA 1)THE PHARMACEUTICALLY ACCEPTABLE ACID ADDITION SALTS THEREOF, AND THE STEREOCHEMICALLY ISOMERIC FORMS THEREOF, WHEREIN XIS O, CH2 OR A DIRECT BOND; R1 IS HYDROGEN OR C1-6ALKYL; R2 IS HYDROGEN, C1-6ALKYL, C3-6ALKENYL OR C3-6ALKYNYL; R3 IS HYDROGEN C1-6ALKYL; OR R2 AND R3 MAY BE TAKEN TOGETHER TO FORM A BIVALENT RADICAL OF FORMULA -(CH2)M-, WHEREIN M IS 4 OR 5; OR R1 AND R2 TAKEN TOGETHER MAY FORM A BIVALENT RADICAL OF FORMULA -CH = CH- OR FORMULA -(CH2)N-, WHREIN N IS 2, 3 OR 4; OR R3 AMY REPRESENT A BOND WHEN R1 AND R2 TAKEN TOGETHER FORM A BIVALENT RADICAL OF FORMULA -CH=CH-CH=, -CH=CH-N= OR -CH=N-CH; R4 IS HYDROGEN OR C1-6ALKYL; A1K1 IS A BIVALENT C1-3ALKANEDIYL RADICAL; A IS A BIVALENT RADICAL OF FORMULA:(FORMULA 2)WHEREIN EACH R5 IS HYDROGEN OR C1-4ALKYL; WHEREIN EACH R6 IS HYDROGEN OR C1-4ALKYL; A1K2 IS C2-15ALKANEDIYL OR C5-7CYCLOALKANEDIYL; AND EACH P IS 0, 1 OR 2; PROVIDED THAT [2-[(2,3-DIHYDRO- 1, 4-BENZODIOXIN-2-YL)METHYL]AMINO]ETHYL GUIDINE IS EXCLUDED. PHARMACEUTICALS WHICH ARE USEFUL AS VASOCONSTRICTOR. COMPOSITIONS COMPRISING SAID GUANIDINE DERIVATIVES AS ACTIVE INGREDIENTS, PROCESSES FOR PREPARING SAID GUANIDINE DERIVATIVES AND NOVEL N-CYANO GUANIDINE, INTERMEDIATES; AND A USE AS A MEDICINE ARE DESCRIBED.