Abstract: Provided are novel dialkyl (dialkoxyphosphinyl)methyl phosphates of formula ##STR1## which am useful as anti-inflammatory and anti-arthritic agents. The compounds are synthesized from the reaction of tetraethyl oxiranylidenebisphosphonate and unsubstituted or alkyl-amines. Representative compounds include 2-(benzylamino)-1-(diethoxyphosphinyl)ethyl phosphonic acid diethyl ester, 1-(diethoxyphosphinyl)-2-[2'-(1', 2', 3', 4'-tetrahydro)napthylamino]ethyl phosphonic acid diethyl ester, 2-(3-fluorobenzylamino)-1-(diethoxyphosphinyl)ethyl phosphonic acid diethyl ester, and 5,5 -dimethyl-2-[2-(3-fluorobenzyl)amino-1-[(5,5-dimethyl-1,3,2-dioxaphosphori nan-2-yl)oxy]ethyl]-1,3,2-dioxaphosphorinane P,2-dioxide.