Laser-induced fluorescence (LIF) excitation spectra of t-C4H9O (tert-butoxy) and 2-C4H9O (2-butoxy) radicals were investigated in the wavelength range 335-400 nm. The radicals were formed by laser photolysis of the corresponding butyl nitrites at 355 nm. For tert-butoxy, 16 vibronic bands in two progressions were labeled. The dominant progression corresponds to C-O stretching mode with v'(C-O) = 521 +/- 10 cm(-1). The transition origin was tentatively assigned at 25 866 cm(-1) (386.6 nm). Numerous bands remain unassigned. The LIF excitation spectrum of 2-butoxy, consisting of 15 vibronic bands in four progressions, was observed for the first time. A C-O stretching frequency v'(C-O) = 567 +/- 10 cm(-1)was obtained from the dominant progression. The transition origin was tentatively assigned at 26 185 cm(-1) (381.9 nm). Three other progressions are evident, which have different vibrational band intervals: 617 +/- 10, 590 +/- 10, and 552 +/- 10 cm(-1) Zero-pressure fluorescence lifetimes for numerous vibronic bands of tert-butoxy and 2-butoxy were determined to be about 150 and 85 ns, respectively. These spectra can be used as a convenient spectroscopic tool for kinetic studies of butoxy radicals and should provide a starting point for investigations of their excited states structure and dynamics.