Deformation and fracture behaviors of ZnO whiskers were investigated by the performance of tensile, compressive, and bending tests. The whiskers could be elastically strained to as much as 15% in bending without undergoing fracture or plastic deformation. They are generally brittle, except in a few cases. Results of compression tests show that slip may take place on the basal plane as well as on the prism plane. In a tensile test a specimen is found to undergo shear along pyramidal planes. Besides the usual planar fracture, a specimen, when failed in tension, showed cup‐and‐cone fracture, which is a feature of ductile materials. On the basis of the available evidence it is suggested that cup‐and‐cone fracture may not be a feature of ductile materials only; it may occur, as in the present case, in brittle materials, with perhaps a different mechanism.