A series of phosphorus-containing 1,2-dihydroxynaphthalenes have been obtained via the reaction of 1,2-naphthoquinone derivatives with tri( n-butyl)- or triphenylphosphine followed by treatment of the intermediate phosphobetaines with various acids. The antimicrobial activity of the synthesized compounds has been studied and the structure—activity relationship established, which gives grounds for the search for new biologically active compounds in this direction.