<p><strong>Objective: </strong>Investigate the influence of the antimicrobial peptides P34 and nisin on the expression of genes associated with components of the cell surface of <em>Listeria monocytogenes</em> and <em>Listeria seeligeri</em>.</p><p><strong>Methods: </strong>Antimicrobial activity was determined by addition of peptide P34 and nisin (12.5 µg/ml) onto Brain Heart Infusion agar (BHI) plates previously inoculated with indicator strains (<em>L. monocytogenes</em> ATCC 7644 or <em>L. seeligeri </em>AC 82/4) after incubation for 24 h at 37 °C or 240 h at 4 °C. Ribonucleic acid (RNA) was directly extracted from bacterial colonies at the border of the inhibition zones, and the expression levels of genes D-alanine-D-alanyl carrier protein ligase<em> (dltA), </em>putative phospholipid lysinylation<em> </em>(<em>Imo 1695</em>)<em> </em>and EIIAB<sup>Man</sup> of mannose-specific PTS<em> </em>(<em>mptA</em>) were determined using real-time PCR.</p><p><strong>Results</strong><strong>: </strong>A non-significant increase in the levels of transcription of genes <em>dltA, Imo1695 </em>and<em> mptA</em> was observed for <em>L. monocytogenes </em>treated with peptide P34 or nisin. Both peptides caused a similar decrease in <em>dltA</em> gene expression in <em>L. seeligeri</em>. The expression of gene <em>Imo1695</em> significantly decreased (about 2000-fold) after treatment with the peptide P34 at 37 °C, while at 4 °C a reduction of 12-fold and 5-fold was detected for P34 and nisin, respectively. A significant decrease in <em>mptA</em> gene expression was observed by exposition to peptide P34 (31.872-fold) and nisin (16.047-fold) for 24 h at 37 °C.</p><p><strong>Conclusion: </strong>The results suggest that both peptide P34 and nisin influence the expression of genes related with the cell-surface/cell-membrane structure of <em>L. seeligeri</em> and in lesser extent <em>L. monocytogenes</em>.</p>