Ferulic acid (C₁₀H₁₀O₄), also known as 4-hydroxy-3-methoxy cinnamic acid, is a phenolic phytochemical found in the leaves and seeds of many plants, particularly cereals such as brown rice, whole wheat, and oats. Ferulic acid has known antioxidant properties and laboratory experiments have shown that ferulic acid is a potent inhibitor of the reaction between nornicotine and nitrite leading to TSNA formation. Experiments were conducted at the University of Kentucky Research and Education Center near Princeton, KY in 2003-2005 with the objective of evaluating the effect of pre-harvest ferulic acid application on TSNA levels in dark fire-cured tobacco. Experiments were conducted using 'Narrowleaf Madole' dark tobacco in a complete block design in the field with 3 replications of treatments. Tobacco was treated 24 hr prior to harvest with ferulic acid (FA) solution at 0.25% or 0.50% FA with a non-ionic surfactant at 0.25% by vol. using small-plot spraying equipment that was calibrated to deliver 50 gal/A (467 L/ha). A non-treated control was included for comparison. Tobacco was stalk harvested 24 hours after application and plots were completely randomized on a single tier of a tobacco barn. All tobacco received forced air from fans for the first 14 to 21 days after housing. Tobacco was then wood-fired, receiving 3 firings over a 14 to 21 day period. The experiment was conducted 6 times. Following curing, whole leaf samples were taken from each stalk position of each plot and leaf chemistry analysis was performed. Averaged across all stalk positions, tobacco treated with pre-harvest applications of ferulic acid solutions had 25 to 60% less total TSNA than non-treated tobacco.