Dibenzofuran has been brominated under standard electrophilic conditions to yield mono- through octabromodibenzofuran. The GC retention indices for ten products have been measured and correlated with the retention indices for the corresponding chloro dibenzofurans. Mass spectra for the eight major products are reported. Brominated dibenzofurans (PBDFs) may be widely dispersed in the environment, arising from oxidative ring closure of fire retardant brominated biphenyls e.g., Fire Master BP6, combustion of other bromine containing materials, from the use of brominated phenols as synthetic intermediates, and other routes analogous to the formation of the chlorinated dibenzofurans (PBDFs). In order to monitor possible environmental contamination by highly toxic PBDFs, authentic analytical chemical standards of these compounds must be available. The authors wish to report the synthesis of certain congeners of mono- through octa PBDFs, mass spectral characteristics of these compounds, and retention indices for these compounds. The retention indices for these compounds were found to correlate well with those of the PCDFs. The correlation was used in a novel application to assign structures while minimizing potential human exposure to these materials.