Surface aeration of pig manure stored in anaerobic lagoons for odour control was experimentally studied in the laboratory. The effects of different aeration rates and depths on reduction in emission of odorous gases were determined for both continuous and intermittent aeration processes. Surface aeration was found to be effective for controlling odours of anaerobic lagoons. Continuous low-rate aeration to maintain the dissolved oxygen in the surface liquid layer at 0.5 to 2.5 mg/litre was effective for odour control but resulted in high ammonia emission rates. Intermittent aeration was found to be a feasible approach to minimize the energy requirement for aeration while still effectively controlling the odours of the manure.