Chitosan catalyzed synthetic procedure has been developed for the synthesis of alpha-hydroxy phosphonates from different aromatic aldehydes and diethyl phosphite at 60 degrees C. The title compounds are characterized by IR, H-1, C-13, P-31 NMR and mass spectral data. All the title compounds 3a-j were tested for their invitro antioxidant activities by DPPH, Nitric Oxide and H2O2 scavenging methods.