In a previous paper, it had been found that completely aliphatic 3-(methylene aminoxy)propanolamine derivatives showed a good beta-blocking adrenergic activity directed prevalently towards beta(2)-tracheal receptors. In an attempt to change the beta-adrenergic properties of these compounds from antagonist to agonist, while still retaining the beta(2)-selectivity, a series of new completely aliphatic 3-(methyleneaminoxy)propanolamine derivatives were designed in which either a hydroxylic or a methoxylic group was present on the aliphatic portion linked to the oximic carbon. The synthesis of the new compounds and their beta-adrenergic activity, evaluated by means of functional tests on isolated preparations, are described and discussed; the results obtained are then rationalised on the basis of their conformational and reactivity characteristics, determined by means of theoretical methods.