BACKGROUND: Noninvasive ventilation (NIV) is the application of mechanical ventilation through a mask. It is used to treat certain forms of acute respiratory failure in intensive care units (ICU). NIV has clinical benefits but can be anxiogenic for the patients. This study aimed at describing cognitive and affective attitudes toward NIV among patients experiencing NIV for the first time in the context of an ICU stay. METHODS: Semi-structured interviews were conducted in 10 patients during their ICU stay and soon after their first NIV experience. None of the patients had ever received NIV previously. Evaluative assertion analysis and thematic analysis were used to investigate cognitive and affective attitudes toward NIV before, during, and after the first NIV experience, as well as patient attitudes toward caregivers and relatives. RESULTS: Before their first NIV session, the cognitive attitudes of the patients were generally positive. They became less so and more ambiguous during and after NIV, as the patients discovered the actual barriers associated with NIV. Affective attitudes during NIV were more negative than affective attitudes before and after NIV, with reports of dyspnea, anxiety, fear, claustrophobic feelings, and reactivation of past traumatic experiences. The patients had more positive attitudes toward the presence of a caregiver during NIV, compared to the presence of a family member. CONCLUSION: This study corroborates the possibly negative-or even traumatic-nature of the NIV experience, with emphasis on the role of affective attitudes. This is a rationale for evaluating the impact of NIV-targeted psychological interventions in ICU patients with acute respiratory failure.