Objective To investigate whether interleukin-1 receptor associated kinase (IRAK) participates the airway mucus hypersecretion induced by lipopolysaccharide (LPS). Methods The expression of Toll-like receptor (TLR)-4 or IRAK was down regulated by the transfection of specific small interfering RNA (siRNA). The transcription level of mucin 5AC (MUC5AC) mRNA as well as the secretion level of MUC5AC protein were judged by reverse transcription polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assay (ELISA), respectively. The activity of signaling molecules involved in TLR-4 associated pathway, such as the phosphorylated IRAK, nuclear translocation of NF-κB p65, was analyzed by Western blot. Results The level of intracellular phosphorylated IRAK was increased by stimulation of LPS in BEAS-2B cells. However, down-regulation of TLR-4 by siRNA could partially attenuate the additional phosphorylation of IRAK induced by LPS (P<0.05). LPS elicited a nuclear translocation of NF-κB p65 in BEAS-2B cells, which could be partially blocked by the down-regulation of TLR-4 or IRAK. With RT-PCR, an increased expression level of MUC5AC mRNA was discovered in wild-type BEAS-2B cells (0.82±0.09) than TLR-4 defect cells (0.36±0.05), IRAK defect cells (0.48±0.05) and IRAK inhibitor pretreated cells (0.57±0.07) (all P<0.05). Meanwhile, according to ELISA, an increased secretion level of MUC5AC protein was recorded in wild-type BEAS-2B cells [(0.76±0.09) μg/L] than TLR-4 defect cells [(0.33±0.04) μg/L], IRAK defect cells [(0.42±0.05) μg/L] and IRAK inhibitor pretreated cells [(0.51±0.06) μg/L] (all P<0.05). Conclusion As an crucial regulator of TLR dependent signaling pathway, IRAK may participate the airway mucus over-synthesis induced by LPS.