Cubic boron nitride (c-BN) nanocrystals have been synthesized by pulsed laser induced liquid-solid interfacial reaction. It is shown that the diameters of the prepared quasi-spherical c-BN nanocrystals vary from 30 to 80 nm via transmission electron microscopy (TEM). The 20 values of the X-ray diffraction (XRD) peaks of the resultant c-BN nanocrystals are 43.16degrees, 74.16degrees, 90.08degrees and 136.1degrees, respectively, corresponding to the (1 1 1), (2 2 0), (3 1 1) and (3 3 1) crystalline planes of a c-BN phase. Fourier transform infrared (FTIR) spectroscopy has also been used to characterize the structure of boron nitride. The formation of c-BN nanocrystals upon pulsed laser ablation at the liquid-solid interface is discussed in detail. (C) 2002 Elsevier Science B.V. All rights reserved.