Background: This study aimed to evaluate burnout in intensive care unit nurses and describe the relationship between burnout dimensions and sociodemographic and professional variables. Methods: A pilot study was carried out with 29 intensive care nurses during the COVID-19 pandemic. The data were collected using an online questionnaire consisting of a sociodemographic characterization and the Maslach Burnout Inventory Human Services Survey. In the comparative statistical analysis, the nonparametric Mann–Whitney and Kruskal–Wallis tests were used (p< 0.05). Results: The Emotional Exhaustion dimension represented an average of 27.9 ± 10.4, and the Personal Fulfillment of 30.8 ± 7.0 was considered high. Regarding Depersonalization, medium-level results (8.1 ± 6.0) were found. There was a prevalence of 41.3% of high levels of burnout. There was no statistically significant difference in the comparison between the three dimensions and sociodemographic and professional variables (p> 0.05). Conclusions: The global results point to high levels of burnout in nurses, with greater expression in the Emotional Exhaustion and Professional Fulfillment domains. There were no differences between groups, demonstrating homogeneity in the team’s level of burnout. The incidence of burnout in this study was higher than that identified in other studies carried out in Portugal with health professionals. This pilot study will allow the defining of strategies for reducing burnout and, consequently, a proposed extension of the study to other organization wards.