Here we report on the formation of fullerenes with a reduced number of layers (typically ⩽ 3) in boron nitride (BN) which was subjected to in situ electron irradiation at 20 and 490 °C in a high resolution 300 kV transmission electron microscope (HRTEM). The BN fullerenes exhibited B/N stoichiometry of ∼ 1 as confirmed by electron energy loss spectroscopy using a 1 nm electron probe. The fullerene HRTEM images revealed rectangle-like shapes when viewed in specific projections, unlike the quasispherical carbon fullerene morphology. The octahedral BN fullerene model [O. Stéphan, Y. Bando, A. Loiseau, F. Willaime, N. Shramchenko, T. Tamiya, and T. Sato, Appl. Phys. A 67, 107 (1998)] is verified by the BN fullerene observations at different viewing angles. © 1998 American Institute of Physics.