Background and Purpose: The aims of this study are as follows: to adapt and validate the psychometric properties of the Spanish version of the Practice Environment Scale of the Nursing Work Index (PES-NWI) adapted to the nursing home environment across seven Spanish-speaking countries and to cross-culturally adapt the Scale of the Nursing Work Index with nurses from seven countries. Methods: Adaptation process and psychometric validation of the instrument included translation and back-translation, content validity, test-retest reliability, internal consistency, and construct validity. Results: A total of 134 nursing homes belonging to the same religious order were randomly selected from seven Spanish-speaking countries with a sample of 378 nurses. The exploratory factor analysis explained a five-factor structure (56% of the explained variance) with adequate goodness-of-fit indices in the final factor solution. Conclusions: The validation process indicates that the Spanish language version of the PES-NWI with five factors and 31 items, for long-term care facilities for the elderly, is valid and reliable in its current version and can be used to measure the environment of nurses working in clinical practice in Spanish-speaking nursing homes.