I L-11 is an anti-inflammatory cytokine which plays important roles during immune response. Previously a significant reduction of IL-11 levels has been reported from periodontal health to disease clinically. The aim of the current study was to evaluate the potential role of IL-11 in the pathogenesis of periodontal disease by determination of IL-11 gene expression levels in human gingival fibroblasts (HGFs) in response to a major periodontal pathogen Fusobacterium nucleatum (Fn) in vitro. HGFs were cultured in a media containing DMEM/F12, 10% fetal bovine serum, 1% Penicillin and Streptomycin and 1% Amphotericin B. Fn (subsp. Polymorphum; ATCC 10953) was obtained anaerobically and diluted with DMEM/F12. HGFs were infected with Fn for 4 hours at 50 multiplicity of infection (MOI) in an antibiotic-free medium. Escherichia coli lipopolysaccharide (LPS) was used as a positive control. RNA isolation was performed and subsequently, cDNA was converted. Relative quantification levels of IL-11 were evaluated by real time-Polymerize chain reaction (rt-PCR). A significant downregulation (2fold) of IL11 was detected in HGFs infected with Fn for 4 hours compared to control group. IL-11 may be dysregulated by Fn, a major periodontal pathogen, therefore may be involved a role in the pathogenesis of periodontal disease.