The purpose of this study was to compare the expression of cytokines and nuclear factor-kappa B (NF-kappa B) subunits in cultured sinus mucosal cells by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) in chronic sinusitis patients with allergic rhinitis (abbreviated as AR patients) versus patients without AR (abbreviated as non-AR patients). The localization of p50 in cultured sinus mucosal cells was also observed by immunocytochemistry. The expression of messenger RNAs (mRNA) encoding granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-6, IL-8, p50 and p65 subunits, and inhibitory kappa B-alpha (I kappa B-alpha) were analyzed by RT-PCR. The proportion of active NF-kappa B-positive cells in the epithelial layer was analyzed using a laser-scanning confocal microscope image system. The levels of GM-CSF, IL-6, IL-8, and p50 mRNAs in AR patients were significantly higher than those in non-AR patients (p < 0.01, p < 0.01, p < 0.01, and p < 0.001, respectively). Immunocytochemical reaction for p50 in sinus mucosal cells in AR patients showed more intense nuclear staining compared to non-AR patients. These findings could support the hypothesis that the increase of cytokines from sinus mucosal cells in AR patients was associated with augmented NF-kappa B mRNA expression, resulting in the modification of the cytokine network.