A series of self-assembled monolayers (SAMs) derived from segmentally perfluorinated alkanethiols, F(CF2)(n)(CH2)(11)SH, where n = 4, 6, 8, 10, on gold was used to measure the attenuation lengths, lambda, of photoelectrons possessing kinetic energies between 900 and 1400 eV in fluorocarbon films. The intensities of the photoelectron peaks from the gold substrates decreased exponentially with increasing n, giving attenuation lengths of 40 Angstrom at 1403 eV, 34 Angstrom at 1151 eV, and 25 Angstrom at 940 eV. The attenuation lengths for photoelectrons in the fluorocarbon films were indistinguishable from those in hydrocarbon films measured with SAMs derived from n-alkanethiols on gold.