Background: A robust safety culture is essential for ensuring high-quality healthcare delivery. From a nursing perspective, especially among critical patients, it fosters ongoing improvement by highlighting areas that need attention. Aims: This study aimed to evaluate the perception of patient safety culture among nurses within the critical care environment. Methodology: An observational study was conducted at a central hospital in Portugal employing the Hospital Survey on Patient Safety Culture (HSPSC) questionnaire. Results: The study encompassed 57, nurses predominantly female (73.7%), aged 25–64. Most participants were general nurses (77.2%), with a significant proportion (61.4%) working in the emergency department and possessing an average tenure of 13 years at the facility. The perception of critical patient safety culture (CPSC) was predominantly positive (40.6%), varying by department, with intensive care nurses reporting the highest positivity rates. Teamwork was identified as a strong point, receiving 80.7% positivity, highlighting it as a well-established domain in the CPSC, whereas other domains were recognised as requiring enhancements. Conclusions: The study pinpointed both strengths and weaknesses within the CPSC, offering a foundation for developing targeted strategies to bolster patient safety culture in critical care settings.