Five commercial pit additive products were examined for effectiveness of controlling the release of odorous and volatile compounds from swine manure. pH, volatile fatty acids, total solids, total volatile solids, total N, and total ammonia N were monitored, and levels of aerial ammonia and hydrogen sulfide were measured. Odor thresholds were determined by a dynamic triangle forced-choice olfactometer. The five products tested reduced the odor thresholds from 58 to 87% as compared with control samples. Three of the five products showed significant reductions in volatile fatty acids (34 44%; P < 0.05). Correlation analysis showed that the odor threshold is not correlated with volatile fatty acids concentrations existing in the swine manure (coefficient of correlation: r = 0.16). Malodor could be produced by certain types of volatile fatty acids not necessarily present in high concentrations. The abatement of ammonia emission from swine manure was not determined in this study due to low pH values for both the treated and control samples.