Background: Non-invasive mechanical ventilation (NIMV) frequently involves the development of pressure ulcer (PU) secondary to face-masks. Its prevention considers the empirical use of protective patches between skin and mask, in order to reduce the pressure exerted by face-masks. Objectives: To evaluate the effect of protective patches on the pressure exerted by face-masks, and its impact on ventilatory parameters. Method: A simulated model of BiPAP using total face mask on a training phantom with a physiological airway model (ALS PRO+) in supine position was used. The pressure on the front, chin and cheek was measured using 3 types of patches commonly used versus a control group, using pressure sensors (Interlinks Electronics(R)). The values obtained with the model of mask-protective patches in the programmed variables (peak inspiratory flow (PIF), expired tidal volume (Vte) and inspiratory positive pressure (IPAP)) were evaluated with a Trilogy 100 ventilator, Respironics(R). The programming and recording of the variables were carried out in 8 opportunities in each group by independent operators. Results: Any decrease in facial pressure with the protective patches used was observed, compared to the control group. Moltopren(R) increased facial pressure at all support points (p < 0.001), increased leakage, decreased PIF, Vte and IPAP (p < 0.001). Hydrocolloid patches increased facial pressure only in the left cheek, increased leakage and decreased PIF. Polyurethane patches did not produce changes in facial pressure or ventilatory variables. Conclusion: The use of Moltopren (R), hydrocolloid and transparent polyurethane protective patches did not contribute to the decrease on facial pressure. A deleterious effect of Moltopren and hydrocolloid patches was observed on the administration of ventilatory variables, concluding that the non-use of the protective patches allowed a better administration of the programmed parameters.