A novel chemiluminescence method combined with the flow injection technique for the determination of carbon monoxide is presented in this paper. The chemiluminescence signal based on the reaction between myoglobin and luminol in an alkaline medium was remarkably enhanced by carbon monoxide. The enhanced chemiluminescence intensity was linear with carbon monoxide concentration in the range from 0.01 to 10.0 pmol.L(-1), and the detection limit was 3x10(-3) pmol.L(-1) (3sigma). The whole process, including sampling and washing, could be completed in 0.5 min with a relative standard deviation of less than 4.0%. The proposed method was applied successfully in the assay of carbon monoxide in human serum and artificial water samples without any pretreatment procedure.