The peculiarities of domain structure of segmented polyurethane-urea/liqid-crystalline polyester (PU/LCP) blends were studied in the LCP concentration range of 1-10%, with different lengths of the flexible moiety. Small- and wide-angle X-ray scattering (SAXS and WAXS) and differential scanning calorimetry were used. The position of the SAXS maximum changes discontinuously with increasing LCP concentration. We suggest that the rigid fragments of the LCP tend to be incorporated into the rigid domains of the PU component with the restriction that only each third or fourth fragment is involved. The part of the LCP molecule that fits in the space between rigid PU domains is stretched and determines the interdomain distance.