Background/purpose: This study was carried out to investigate whether toll-like receptor-1 (TLR1) rs4833095 (N248S) variant, common in the Taiwanese population, contributes to pathogenesis of allergy. Methods: TLR2/1 ligand Pam3CSK4-stimulated cytokine production in peripheral blood mononuclear cells and monocyte-derived dendritic cells of different genotypes were measured via enzyme-linked immunosorbent assay. Ninety-three Taiwanese allergic patients (with asthma, allergic rhinitis, or atopic dermatitis) and 76 controls were recruited for genotyping. Serum immunoglobulin E (IgE) levels were evaluated in 60 allergic patients. Results: The homozygous TLR1 C variant allele carrier had increased Pam3CSK4-induced tumor necrosis factor-alpha and interleukin-12 responses in peripheral blood mononuclear cells and monocyte-derived dendritic cells, respectively. Furthermore, although the C/C genotype was not associated with susceptibility to atopic diseases, it was correlated with lower total IgE levels in sera of allergic patients. Conclusion: Our data suggest that the TLR1 N248S polymorphism might play a role in Th1/Th2 differentiation, and the determination of serum IgE levels. However, interactions with other genetic and environmental factors might be required to contribute to risk of allergic diseases in our population. Copyright (C) 2015, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC.