Static headspace sampling and gas chromatograph (GC) analyses were used to monitor the concentration of malodorous compounds (volatile fatty acids (VFA), phenol, p-cresol, indole, and skatole) throughout the aerobic treatment of swine wastewater. In two sets of experiments, continuous aeration of the wastewater was carried out for 24 h. An addition of sodium azide, a microbial inhibitor, was made in the second experiment in order to explore the impact of microbial activity versus air stripping on the concn of volatile compounds. Results confirm that static headspace sampling and GC separation provide a useful method for monitoring the treatment process, and that aeration is an effective method of odour control for swine wastewaters. Under aerobic conditions, malodorous VFA, phenol, p-cresol and skatole were degraded. The significant decline in the rate of degradation of acetic acid in the second experiment can be attributed to a decline in microbial activity.