Already in the 1990′s, the Fusion Project Evaluation Board recognised the need for social research to gain understanding on public opinion towards fusion and on elements that can contribute to build trust among the different actors in the field. The SERF program (Socioeconomic Research on Fusion) was then started. In 2014, public awareness and acceptance of fusion energy was re-confirmed by EURO fusion as crucial, for both sociological research and the fusion community. Given that fusion is not a hot issue among most publics, it is little known and distant from daily life, properly researching public attitudes towards fusion entails important methodological challenges. To address these challenges, this paper uses a combined qualitative- quantitative approach to examine public attitudes towards fusion. Data were collected with open and closed questions included in a survey among Belgian adults (N=365 respondents who said they had previously heard of fusion energy), using Computer Assisted Personal Interviews. The quantitative analysis showed that the most influential predictors of attitudes towards fusion are the attitudes towards nuclear energy, the attitudes towards science and technology, and the perceived importance of costs and time needed to develop fusion energy. Our qualitative evidence confirms that nuclear fission does play a key role in the sense making about fusion, as a key device to define fusion was its comparison with fission (either as a new, different, nuclear or as a still dangerous nuclear). The results also showed some evidence that a new ‘fusion brand’ emerged spontaneously among the survey participants; respondents who mobilised the new brand referred to fusion as endless and clean energy that could solve our energy problem, and as scientific progress. Based on results, we discuss implications for fusion research and development.