Commercially available silica glass microstructured optical fibers with birefringence caused by filling factor asymmetry may be used in optical fiber sensors. Nevertheless, their compatibility with soft polymers is rather poor. Better fitting needs to be obtained between optical fibers and materials with smaller Young modulus. High birefringent microstructured polymer optical fibers with, understandably, a relatively very small Young modulus are quite well-known but their technology and sensor properties are rather slightly advanced [1]. The paper presents the technology of manufacturing high birefringent microstructured polymer optical fibers mPOF HB from polymethylmetacrylate (PMMA). The fabricated fibers were characterized from the point of optical, transmission and sensor properties. © 2009 Photonics Society of Poland.