The concept of sustainability includes many different definitions and diversified perspectives with its ecological, economic, social, and cultural dimensions. However, building positive attitudes towards sustainability is important to fulfill broad and comprehensive sustainability goals. The present study aimed to determine the meanings that pre-service teachers ascribed to the concept of sustainability. The study applied an explanatory mixed-method design. In the quantitative part of the design, preservice teachers' compositions regarding sustainability were analyzed using document analysis. In the qualitative part of the design, a scale was developed and evaluated using the survey method. Data of the study were collected using the Emotional Semantic Difference towards Sustainability Scale. The scale consisted of 13 two-tailed pairs of opposite adjectives ranging from very positive, quite positive, slightly positive, neutral, slightly negative, quite negative, and very negative. The Cronbach Alpha reliability coefficient of the scale was calculated as 0.94. The study data were analyzed using SPSS 27 software. The results revealed that the preservice teachers ascribed positive but mostly slight emotional semantic values to the concept of sustainability. The preservice teachers most ascribed the positive meanings of important, useful, and clean to sustainability. Also, they ascribed the negative meaning of Complex to sustainability. This situation can be read as the preservice teachers' perspective towards sustainability is generally positive, as well as experiencing problems in perceiving the concept.