In order to analyze the composition of landfill gas (LFG) with respect to malodorous components, the concentrations of several reduced sulfur compounds (RSC: hydrogen sulfide (H 2 S); methyl mercaptan (CH 3 SH); dimethyl sulfide ((CH 3 ) 2 S); carbon disulfide (CS 2 ); and dimethyl disulfide ((CH 3 ) 2 S 2 )) were determined from four municipal landfill sites—initialed W, B, H, and N—in Korea. The S gas concentrations measured in these landfill sites were found consistently to be dominated by H 2 S, while their absolute mean values tended to change considerably between one inactive site (N) and the others; its mean values were measured from as little as 336ppb (N site) up to 2340ppm (H site). Hence, in terms of mass concentration units (mgm −3 ), H 2 S alone generally explained far more than 90% of all S gases determined concurrently. If the relative contribution of RSC to the LFG budget is assessed in relation to major aromatic hydrocarbons (e.g., benzene, toluene, and xylene), the RSC emission appears to comprise a significant proportion as trace components of LFG other than major ones like CH 4 and CO 2 .