Hyperplastic scar, a fibroproliferative disorder, complicates wound healing. Although the pathogenesis is not well understood, prolonged inflammation is a known contributing factor. Emerging evidence suggests that fibroblasts regulate immune/inflammatory responses through toll-like receptor 4(TLR-4) activated by lipopolysaccharide (LPS), leading to nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPK) activation, cytokine gene transcription and co-stimulatory molecule expression and resulting in inflammation. So the possible roles of TLR-4 in hyperplastic scar formation need to be explored. Paired normal and hyperplastic scar tissue was collected and dermal fibroblasts isolated and cultured. Quantitative RT-PCR of pairs of fibroblasts demonstrated mRNA levels for TLR4 and its legend myeloid differentiation factor 88 (MyD88) in hyperplastic scar fibroblasts (HSFB) were increased significantly compared with normal fibroblasts (NFB). When paired normal and HSFB were stimulated with LPS, significant increases in mRNA and protein levels for TLR-4, MyD88, transforming growth factor-beta1 (TGF-β1) and Ⅰ procollagen were detected. However, when transfected with MyD88 small interfering RNA (siRNA) in HSFB, then stimulated with LPS, a significant decrease in mRNA and protein levels for these molecules compared to only LPS-stimulated fibroblasts was detected. In comparison, a scramble siRNA transfection did not affect mRNA or protein levels for these molecules. Results demonstrate LPS stimulates proinflammatory cytokine expression in dermal fibroblasts and MyD88 siRNA eliminates the expression. Therefore, controlling inflammation and manipulating TLR signaling in skin cells may result in novel treatment strategies for hyperplastic scar.