Optical fiber cantilevers with uniform diameters are fabricated using an etching method. Resonant frequencies of the optical fiber cantilevers with different lengths and diameters are calculated with the flexural wave theory of elastic beams. An experimental system is built for measuring the spectrum of the resonant frequencies of the optical fiber cantilever. Two optical fiber cantilevers with diameters of 8.8 and 11 &mgr;m and lengths of 568 and 776 &mgr;m, are examined separately with the system. The measurements agree well with theory. The experiments show that the higher vibrational modes of the optical fiber cantilever can be excited with high amplitude, which is well suited for sensing purposes. ©1998 American Institute of Physics.