<p><strong>ABSTRACT. </strong><em><strong>Background</strong></em>: due of capsaicin effect on the control of various inflammatory mediators, it has been proposed to modulate inflammatory processes caused by physical assaults to pulp tissue. <em><strong>Purpose</strong></em>: to evaluate the effect of capsaicin diluted in 0.05 % ethanol and its vehicle on PGE<sub>2 </sub>production, IL-8, IL-6, IL-1β, and IL-12p70 in Human Fibroblasts Pulp (FPH). <em><strong>Methods</strong></em>: concentrations of PGE2, IL-8, IL-6, IL-1β, and IL-12p70 were analyzed by ELISA or flow cytometry in supernatants of FPH at 6 and 8 hours, after being stimulated with capsaicin 5*10<sup>-5</sup> M and 2,5*10<sup>-5</sup> M and ethanol 0.05% vehicle of capsaicin and compared with unstimulated cells. <em><strong>Results</strong></em>: ethanol 0.05% as a diluent capsaicin, is responsible for the effect on the decrease in the expression of PGE2, IL-8 and IL-6 at the times and concentrations evaluated; and IL-12p-70 was the only cytokine that increased significantly in the presence of capsaicin 2,5*10<sup>-5</sup> M at 8h, it is statistically greater than ethanol 0.05%. Capsaicin and ethanol had not significant effect on IL-1β. <em><strong>Conclusion</strong></em>: the effect of capsaicin on FPH, is associated with ethanol 0.05% used as diluent and varies depending on time and the mediator analyzed.</p>