Aim: This study aimed to evaluate the perception of the work environment among intensive care unit (ICU) nurses in Slovakia and identify factors that influence their evaluation. Design: A cross-sectional descriptive study. Methods: The study was conducted between July and October 2023 using the Practice Environment Scale-Nursing Work Index (PES-NWI). Data were collected from 153 ICU nurses across four hospitals. Descriptive statistics, correlation analysis, and nonparametric tests were used for data analysis. Results: The work environment received a generally positive evaluation, with collegial nurse-physician relations receiving the highest ratings, whereas staffing and resource adequacy scored the lowest. Significant correlations were found between job satisfaction, satisfaction with material resources, and perception of patient safety and positive evaluations of the work environment (p ≤ 0.05). Multiple regression analysis identified job satisfaction, satisfaction with material resources, and patient safety evaluation as key predictors of a positive work environment (p ≤ 0.05). Conclusion: These findings underscore the importance of addressing staffing adequacy, resource availability, and leadership support to improve the work environment for ICU nurses, with implications for both nurse retention and patient outcomes.