Novel 1-aryloxy-3-amidoalkylamino-2-propanol derivatives, processes for their manufacture, pharmaceutical compositions containing them and methods of using them in the treatment of heart diseases. The compounds possess .beta.-adrenergic blocking activity and some of them additionally possess cardiac stimulant activity. Representative of the compounds disclosed is 1-phenoxy-3-.beta.-isobutyramidoethylamino-2-propanol.