A bright and highly monochromatic red organic electroluminescent device based on a poly (N-vinylcarbazole) host was made. The device structure consists of poly (N-vinylcarbazole) dispersed with a europium complex, a triphenyldiamine derivative and 1,3,5-oxadiazole derivative as an emitting layer, a hole blocking layer of 1,2,4-triazole derivative and an electron-transporting layer of 8-hydroxyquinoline aluminum. The brightness of this device exceeds 500 cd/m(2) under d.c. voltage conditions. This is the highest brightness reported for a polymer dispersed with a europium complex device. Possible reasons for obtaining such high brightness were analyzed.