Environmental pollutants particularly in the air are one of the most important concerns in all societies. Due to their harmful effects on human’s health, they may also cause changes in climate and environment and therefore it is important to made attempts to halter and control of the pollutants. In this respect, biological methods due to high performance and low cost are of the interest and therefore in this study the biofilteration process was used for its feasibility of degradation of vinyl chloride as a hazardous material in the air stream. This system consisted of three biofilters arranged in series – parallel way that allowed accessing the current of food and moisture all over the bed points. These biofilters was biotrickling type and a continuous flow of liquid was established to flow on the bed. Granular activated carbon mixed with vermicompost, were employed as carrier bed. Microorganism of the process was obtained from a composite of two types of activated sludge, one from the Abadan petrochemical and Isfahan refineries. Dimensions of the biofilter were in pilot-plant scale and liquid and gas flows were as co-current from top to bottom. During testing of the system, variables such as temperature, pressure, pH, liquid and gas flow rates and vinyl chloride concentrations in input and output gas stream of each column were measured. The results indicated that during the 110 days, the system was able to remove over 35% of inlet vinyl chloride that with regard to the low degradability of chlorinated organic compounds is considerable. Maximum elimination capacity values were calculated for each of the three corresponding columns which were 0.8, 0.45 and 0.5 gr/m3.hr respectively. Elimination capacity values for one minute empty bed residence time and the flow rate of gas input 0.45 m3/hr were also obtained. The results also showed that by increasing of bed length removal efficiency is also increased and concentration of output gas is decreased. The chlorine amount in the liquid flow returned from columns showed that during three days, 18mg Cl-/lit chlorine was added in the reservoir. Theoretical mass balance of chlorine around the system also confirmed this result. Key words: Biofilteration, Biotrickling Filter, Vinyl Chloride, Gas Pollutants, Granular Activated Carbon