Real-time wide-angle X-ray diffraction (WAXD) measurements during blown film extrusion of low-density polyethylene are reported in this study. WAXD patterns were obtained at different axial positions in the blown film line starting from a location near the die and extending up to the nip-roller. The X-ray diffraction patterns from the bubble were analyzed for crystalline growth along the bubble. From the evolution of (110) and (200) peaks, it is evident that the crystallization process starts near the frost-line height (FLH), shows a steep growth immediately past the FLH, and then plateaus at higher axial distances near the nip-rolls. The real-time crystallinity profiles obtained from WAXD were consistent with those measured using real-time Raman spectroscopy.