Background and Purpose: This study adapted the Nurse Practitioner Primary Care Organizational Climate Questionnaire to measure the organizational climate of nurse practitioners in acute care settings and validated the Nurse Practitioner Acute Care Organizational Climate Questionnaire (NP-ACOCQ). Methods: We used a three-phase instrument adaptation design. In phase 1, experts assessed face and content validity. In phase 2, pilot testing enabled item analysis and preliminary reliability testing. In phase 3, field testing supported exploratory factor analysis. Results: The NP-ACOCQ had a three-factor structure representing subscales. The subscales had Cronbach's alphas of 0.87, 0.90, and 0.94. The subscales, Institutional Visibility, Interprofessional Relationships, and Organizational Autonomy each had between 5 and 13 items. Conclusions: The NP-ACOCQ is a valid and reliable measure to assess organizational factors determining the acute care nurse practitioner work environment.