This study investigated the causal relationships between international tourists’ perceived sustainability of Jeju Island, South Korea and environmentally responsible behavior, revisit intention, and positive word-of-mouth communication. Perceived sustainability was employed as a multidimensional construct comprised of economic, cultural, and environmental aspects. Data were collected from international tourists that visited Jeju Island. The results indicated that environmentally responsible behavior was influenced positively by cultural sustainability, and negatively by environmental sustainability. Revisit intention and positive word-of-mouth communication were significantly affected by the three dimensions of sustainability. Based on the findings, associated implications were suggested for sustainable destination management of Jeju Island.