The use of fuel additives is a well-established method for reducing particulate emissions produced in combustion systems. In the present study, the effects of organic fuel additives on soot emissions were investigated in a high-pressure model gas turbine dump combustor and an atmospheric turbulent spray burner using a laser extinction technique. The base fuel used in the current experiment was JP-8 which had a carbon to hydrogen ratio of approximately 0.48 determined directly by C-H analysis. Four additives were systematically investigated: the JP-8+100 thermal stability package (TSP), ethanol, diethyl maleate and an off-the-shelf commercially available additive consisting mainly of nitroalkanes, cyclohexanone, toluene, and dichloroethane (CAA). Measurements of the soot concentrations produced in the combustor at a location of 248 mm downstream from the dump plane indicated that the JP-8+100 thermal stability package, ethanol, and diethyl maleate did not lead to a measurable reduction of soot. In contrast, CAA showed a reduction of up to 30% in soot volume fraction. In addition, as part of the current study, reductions in soot concentrations were also investigated using an atmospheric turbulent spray burner. This experiment focused on testing the major components of CAA in order to isolate those components which are most effective in reducing soot concentrations, and to verify the overall effectiveness of CAA on soot reduction. It was found for the atmospheric turbulent spray burner, that of the components tested, cyclohexanone showed the most potential as an additive. However, no single component was found to be exclusively responsible for the soot reductions. The effect of the CAA on the pollutant emission when added to the JP-8 base fuel was also studied. The results indicated that there is a significant increase of NOx resulting from the CAA addition.