The evolution of misorientation along the solidification front was examined using high-resolution diffraction imaging, the novel technique based on series X-ray topography images. Cylindrical (ø11 mm x 220 mm) single-crystal cast made from nickel-based CMSX-4 superalloy was used for this investigation using standard industrial Bridgman investment casting. Nine cross-sections were prepared from the obtained rod. The high-resolution misorientation maps reveal that the mosaic pattern evolved during the crystallization. The accumulated misorientation was stable at about 2.2-2.8 deg. from a very early stage of the growth process up to about 5 deg. at the end of crystallization. There was no clear evidence of the linear crystal perfection degradation after primary dendrites from the selector reached the mold wall. The highest misorientation appeared at the end of the cast as lines of dendrites whose growth started from the divergent side of the mold.