The aim of this study was to investigate how career-related instruction implemented in secondary school chemistry education concerning water issues influences students' career awareness and their interest towards science learning. This case study is part of a larger design-based research study for the EU-MultiCO project, which focuses on promoting students' scientific career awareness and attractiveness by introducing them to career-based scenarios at the beginning of the instruction unit. The participants in this study were three eighth-grade classes with 46 students in total, and 2 science teachers. Data consisted of observations throughout the intervention and a questionnaire which the students took afterwards. Descriptive statistics taken from the questionnaire were used together with the content analysis of open questions and observation notes. The results reveal that the students acquired knowledge about science, science-related careers and working life skills and that they enjoyed studying chemistry and engaged in learning during the intervention. The students recognized the need for professionals and their responsibilities as well as the importance of water-related issues as global and local problems, but these issues were not personally important or valuable to students. The type of career-related instruction discussed in this paper can give guidelines for how to develop teaching to promote students' science career awareness, trigger students' interest and engage them in science learning.