A new series of 1H-3-(4’-substituted phenyl)-5-(6’’-methoxy napthaline)-2-pyrazolines (4a-e) and 1H-3-(4’-substituted phenyl)-5-(6’’-methoxynapthaline)-2-isoxazolines (5a-e) were synthesized by reacting 1-(4’-substituted phenyl)-3-(6’’-methoxynapthaline)-2-propene-1-one (3a-e) with hydrazine hydrate and hydroxylamine hydrochloride respectively. All these compounds were characterized by means of their IR, 1H NMR, spectroscopic data and microanalysis. All the synthesized products were evaluated for their antimicrobial activity. All the compounds exhibited significant to moderate antimicrobial activity.