Published 2018. This article is a U.S. Government work and is in the public domain in the USA. Favorable nursing practice environments have been associated with lower patient mortality, failure to rescue, nurse-administered medication errors, infections, patient complaints, and patient falls. Favorable environments have also been associated with higher nurse-reported care quality and patient satisfaction in civilian hospitals. However, limited information exists on the relationship between favorable nursing practice environments and positive outcomes in military facilities. Using 4 years of secondary data collected from 45 units in 10 Army hospitals, generalized estimating equations were used to test the associations between nurses’ scores on the Practice Environment Scale of the Nursing Work Index (PES-NWI) and patient outcomes of falls with and without injury, medication administration errors with and without harm, and patient experience. Four significant associations were found between the PES-NWI subscales and the patient outcomes under study. The Staffing and Resource Adequacy subscale was significantly associated with patient falls, the Collegial Nurse Physician Relations subscale was significantly associated with the rate of nurse-administered medication errors, and the Nursing Foundations for Quality Care and Collegial Nurse Physician Relations subscales were both significantly associated with patient experience with nursing care. As in civilian hospitals, favorable nursing practice environment was associated with improved patient outcomes within these military nursing units.