Polymer micro-fibers with inscribed Bragg gratings are reported in this paper. By implementing a two-stage fabrication process a 16 μm diameter micro-fiber is fabricated with an inscribed 10 mm long Bragg grating which exhibits a peak reflected wavelength circa 1530 nm. The growth dynamics of the polymer micro-fiber Bragg grating are also observed and analyzed. A maximum reflectivity of 5% is obtained after an exposure time of 3 minutes to a 50 mW power He-Cd laser of 325 nm wavelength. The temperature characterization of the micro-fiber Bragg grating with different diameters is also presented. The fabricated micro-fiber Bragg grating can be used as sensors for high sensitivity measurements in a number of application areas. © 2013 SPIE.