In this preliminary work, an enteric polymer has been used for encapsulating bovine serum albumine (BSA) as a model protein drug. Poly (lactide-co- glycolide) has been commonly used for oral administration purposes as a polymer matrix, but in this case an enteric polymer was used effectively to protect the protein in a gastric environment. A modified water/oil/water technique was used to decrease the particle diameter, and transmission electron microscopy experiments showed that the average diameter of the nanoparticles obtained was below 100 nm. The spherical nature of the particles and their diameters strongly depend on the control of the process parameters. The encapsulation efficiency was 77% for sample B4, and protein release profiles for both samples B3 and B4 indicate that these systems possess controlled-release characteristics. Finally, as a result of electrophoresis (SDS-PAGE), the BSA was not chemically affected under encapsulation conditions.