This paper reports on research designed to investigate the capacities of different kinds of peat to remove odor-causing compounds from liquid swine manure (LSM). Two experiments were conducted. In experiment #1, five different peat types (both wet and dry) representing a wide range of properties were tested. Eight percent slurries (of peat/LSM) were measured for odor changes at 6, 24 and 96 hours using odor panel and GC/FID analysis. Experiment #2 was designed to determine more precisely the kinds of odor-causing compounds that were changing during treatment. Two extremely different wet peat types were tested in eight percent slurries after 24 hours of treatment. Odor changes were evaluated using both an odor panel and GC/MS head-space, solid-phase, microextraction (HSM). The GC/FID and odor panel results indicated that wet peats were much more effective in removing odor-causing compounds from LSM than were dry peats. Wet peats significantly reduced the LSM odor intensity after 6 hours of treatment, and completely eliminated odors after the 24 hour treatment. The results from the GC/MS HSM method (experiment #2) confirmed the results from experiment #1 and also, allowed us to more precisely identify the specific odor-causing compounds being reduced and to distinguish specific changes in these compounds between peat types. Of the 23 malodorous compounds identified in experiment #2, all showed significant reductions; however, one peat was better at reducing 10 of these, while the wet North Carolina peat was better at reducing 9 others. These results suggest that improvements in odor removal efficiency and costs can be achieved by selection of specific peat types for a specific LSM site.