This paper examines Swedish secondary students’ interest in science and technology from a gender perspectivein a comparative research design using quantitative data collected 2003 and 2020. National datahas been collected from 610 15-year-old students in 2020 as part of a large-scale comparative researchproject, the Relevance of Science Education - Second (ROSES) and compared with data from the Relevanceof Science Education (ROSE) study from 2003. The results empirically update the research field and showa reoccurring interest pattern with minor changes. Content related to space and unexplained phenomenaare still ranked as interesting to learn about. Girls are interested in health issues and the human body,space, dreams and the human soul. Boys favour items about space, inventions and discoveries togetherwith ABC weapons. Minor developments are that interest in learning about diets and exercise as wellas technology has declined. The least interesting things to learn are almost the same as in 2003, with several topics connected to the national science curriculum. The character of students’ interest in S&T isframed and discussed using the theoretical approach of science identity. The stable character with minorchanges is discussed as reoccurring science identities interpreted by the differentiation hypothesis of the“person-object theory of interest”. Gender differences are interpreted as collective identities shown to be‘domain specific’ not ‘subject specific’ and the content level of analysis provide specificity to ‘interest patterns’which has not been well described earlier in the research literature. Research consequences of thisconceptualization and implications for school practice is critically discussed. A research implication fromthis conceptualization is the importance for future studies to investigate varieties of collective identities.