Organic chicken production facilities must provide an access to open air areas (outdoor runs) as specified in European Council Regulations. Yet, very few data on pollutant gas emissions by organic poultry production are available, especially concerning the outdoor runs. To assess trace gas emissions (NH3, N2O, CH4) from an organic broiler housing, gas concentrations were monitored using a photo-acoustic infrared analyser. Air flow rates were estimated using SF6 tracer gas. Concerning the outdoor run, N2O and CH4 emissions were measured using manual static chambers placed on the grassland. Concerning the housing, cumulated emissions of N-NH3 were 0.22, 1.72 and 4.01 g of N per broiler respectively for each measurement period. N-N2O emissions represented 1.09, 0.09 and 0.08 g of N per broiler respectively. CH4 emissions were very low and represented 0.01, 0.33 and 0.34 g of CH4 per broiler, respectively. On the outdoor-runs, emissions of N2O and CH4 were very low although peaks of emission were measured, especially on chambers close to the housing where faeces excretion is higher. Mass balances for N, P, K, Cu and Zn at the system level will be carried out in order to validate these results.