Releases rates of Hydrogen sulfide (H2S) and sulfur dioxide (SO2) from finishing swine manure of two different solid contents and two initial manure accumulation days were measured under laboratory conditions for one month. Manure was stored in reactors of 122 cm height and 38 cm diameter. The reactors were continuously ventilated with 7.7 litres/m of fresh air. Temperature was controlled at 20 degrees C. Mean H2S release in all manure treatments ranged from 75 to 146 micro g/h per reactor or 0.7 to 1.3 mg/h per m2 of manure surface. The effect of manure solid contents and initial manure accumulation days on H2S releases was not consistent. Mean SO2 release in the four manure treatments ranged from 24 to 30 micro g/h. The effect of manure solid contents and initial accumulation days on SO2 releases was not significant. There were evident fluctuations of H2S and SO2 releases during the test. High gas release rates occurred about two days after initial manure addition. High gas releases were also observed after some weekly manure additions.