Nanostructured boron carbide/C60 (B4C/C60) and cubic boron nitride/C60 (c-BN/C60) carbon-ceramic composites were prepared by a high-energy ball milled pre-treatment of the parent materials with the addition of a CS2 solvent followed by a high-pressure/high-temperature (HPHT) treatment. Tthe elastic moduli were calculated based on the experimentally measured density and velocity values of the longitudinal and transverse bulk acoustic waves (BAW) in the specimens. The BAW velocities were measured with a pulse-echo method by laser optoacoustic excitation of ultrasonic pulses. Acoustic microscopy was used to visualize the bulk microstructure and internal defects and to measure the local values of BAW velocities of specimens on which the elastic moduli had been calculated and compared with the data defined by the pulse-echo method. The microhardness and flexural strength of the samples were measured also.