This study used a two-round modified Delphi technique with a questionnaire survey in order to reach a consensus for the questionnaire; the survey was conducted from September to December 2009. The six indicators for the environmental quality of longterm care institutions in Taiwan are (1) indoor environmental quality, (2) safety equipment for the prevention and management of disasters occurring in residents' daily lives, (3) provision for assistive devices for residents' daily use, (4) provision for privacy and individualized space, (5) provision for comfortable and decorated indoor environments, and (6) provision for social interaction space. The scale included 34 items with an acceptable number of panel members and acceptable construct validity. Panel members all highly approved of Indicators 1, 2, and 6. Although they approved of Indicator 3, they suggested that caregivers at institutions should replace the functions of living assistive devices. They approved of Indicator 5; however, they questioned the method for providing comfortable and decorated environments. They approved of Indicator 4; however, they suggested that private space need not be provided in the living room of the institution. In terms of long-term care institution environments in Taiwan, Indicators 1, 2, and 6 were important for protecting residents' physical and psychological well-being and improving