We report the formation of crystalline inclusion compounds (ICs) between the small-molecule host urea (U) and two block copolymer guests : (i) poly(epsilon-caprolactone)-polybutadiene (PCL-PBD) and (ii) PCL-poly(ethylene oxide)-PCL (PCL-PEO-PCL). Both block copolymer-U-ICs are formed by cocrystallization from saturated solutions of urea, and each block copolymer-U-IC was observed with DSC, X-ray diffraction, and C-13 NMR and FTIR spectroscopies. It was found that both blocks of the PCL-PBD diblock copolymer are included in the U-IC channels while only the terminal PCL blocks of the PCL-PEO-PCL triblock copolymer are included. The structure of the PCL-PBD-U-IC appears to be a combination of the traditional hexagonal form with narrow ca. 5.5 Angstrom channels surrounding the PCL blocks, while the PBD blocks are included in an "expanded tetragonal" structure observed previously for PEO(oligomer)-U-IC and polypropylene-U-IC, where the urea matrix channel diameter is believed to be expanded beyond 7 Angstrom. This might explain how the PBD blocks, which contain 12% 1,2 units with bulky -CH=CH2 side chains, are accommodated in the U-IC channels. Similarly, in the PCL-PEO-PCL-U-IC, where only the terminal PCL blocks are included, the IC structure appears very similar to the usual narrow channel, hexagonal structure as found, for example, in PCL-U-IC, the IC between the PCL homopolymer and urea. As a consequence, we may observe PCL blocks in two distinct U-IC environments and may compare their behaviors to those of PCL chains in the homopolymer PCL-U-IC and homopolymer and block copolymer bulk crystals. In addition, T-1 rho measurements of H-1 spin diffusion reveal structural aspects of the block copolymer-U-ICs, and the isolation of U-IC included polymer chains from their neighbors may permit the probing of 1-dimensional H-1 spin diffusion by observing the T-1 rho(H-1) relaxation in these block copolymer-U-ICs.