The effect of Alq(3) deposition rate on the performance of the devices has been investigated by using the organic light-emitting diodes of indium-tin-oxide/N,N'-bis-(1-naphthyl)-N,'-diphenyl-1,1'-biphenyl-4,4'-d iamine/tris-(8-hydroxyquinoline) aluminum (Alq(3))/Mg:Ag. When the Alq(3) deposition rate decreased from about 1.33 to 0.05 Angstrom/s, the luminance efficiency of the devices decreased from 4.75 to 2.0 ed/A. Atomic force microscopy observations showed that Alq3 films prepared at the deposition rates of 1.33, 0.05, and 0.01 Angstrom/s had a root-mean-square roughness of 12.0, 32.0, and 36.6 Angstrom, respectively. X-ray photoelectron spectroscopy measurements showed that as Alq3 deposition rate decreased from 1.33 to 0.01 Angstrom/a, the film contained more N-containing species. These changes in film morphology and chemistry are suspected to be responsible for the change in the electroluminescent performance of the devices.