The precursor dipeptides of RGD, Boc-Arg-Gly-OEt and Ac-Gly-Asp-diOMe, were synthesized in three reverse micellar systems using different proteases. The reaction conditions for the Boc-Arg-Gly-OEt synthesis catalyzed by alcalase and for Ac-Gly-Asp-diOMe synthesis catalyzed by trypsin in AOT/isooctane reverse micelles were optimized by examining the effects of several factors including water content, temperature, pH, reaction time, and the enzymes on the dipeptide yields. The best yields for alcalase-catalyzed synthesis of Boc-Arg-Gly-OEt and trypsin-catalyzed synthesis of Ac-Gly-Asp-diOMe were 62.7% and 78.8%, respectively. Two other reverse micelle systems, Triton/ethyl acetate and HTAB/heptane/hexanol were also tested for the syntheses of the same dipeptides.