Background This study is part of a project entitled "SoLiDe ICU – Sound, Light, and Design in Intensive Care Units" (https://www.gu.se/en/research/solide-icu-sound-and-light-design-in-intensive-care-units), aiming to improve the care environment and its impact on staff health and well-being. The care environment plays a vital role in supporting healthcare professionals in care delivery. However, it appears to be a lack of knowledge concerning how the care environment may influence the provision of person-centered care in this specific setting. Although tools exist to evaluate care environments and person-centeredness separately, there is a lack of instruments specifically designed to evaluate how the ICU care environment supports person-centered care. Aim To validate a questionnaire measuring the impact of the ICU care environment on the provision of person-centered care. Methods A cross-sectional, quantitative study was conducted. Critical care nurses (n=40) completed a digital questionnaire and provided feedback as part of the validation process. Quantitative data were analyzed using SPSS, including reliability testing with corrected item-total correlation and Cronbach’s alpha. Qualitative content analysis was applied to open-ended responses. Results The questionnaire was found generally relevant and understandable. Although some questions were regarded as irrelevant or less suitable for the context of ICU. Statistical analysis indicated high to very high internal consistency across several domains. The participants indicated that items on work environment and collegial climate need to be added and described comprehensively in future versions of the questionnaire. Conclusion This study provides preliminary validation of an instrument aimed at measuring how the ICU care environment supports person-centeredness. Further revisions and validation are needed, before it can be considered as a reliable tool for examining the impact of the care environment as an element in providing person-centered care in the context of intensive care. However, the questionnaire shows a potential for evaluating and improving person-centered practices in intensive care environment.