The distribution and transport of selected hydrophobic halogenated organic compounds on suspended sediment from the lower Mississippi River were determined using discharge-weighted sampling with concurrent discharge measurements. Trends in compound concentration from upstream to downstream and the effects of selected tributaries were determined. The compounds identified on the suspended sediment include pentachlorobenzene, hexachlorobenzene, pentachloroanisole, dacthal, chlordane (trans-), nonachlor (trans-), chlorthalonil, and penta-, hexa-, hepta- and octachlorobiphenyls. Loads of most of the compounds increased from upstream to downstream on the main stem of the Mississippi River. Of the tributaries studied, the Ohio River had the most significant effect on the loads.The distribution and transport of selected hydrophobic halogenated organic compounds on suspended sediment from the lower Mississippi River were determined using discharge-weighted sampling with concurrent discharge measurements. Trends in compound concentration from upstream to downstream and the effects of selected tributaries were determined. The compounds identified on the suspended sediment include pentachlorobenzene, hexachlorobenzene, pentachloroanisole, dacthal, chlordane (trans-), nonachlor (trans-), chlorthalonil, and penta-, hexa-, hepta- and octachlorobiphenyls. Loads of most of the compounds increased from upstream to downstream on the main stem of the Mississippi River. Of the tributaries studied, the Ohio River had the most significant effect on the loads.