This study explores the views of Indonesian junior high school pre-service science teachers (PSTs) towards teaching based on socio-scientific issues (SSIs). Questionnaires were analyzed qualitatively and descriptively. The PSTs (N=62) acknowledged that student competencies ranging from personal to socially relevant skills as well as character formation can potentially be developed through SSI-based instruction. The PSTs mentioned several challenges which may hinder implementation of SSI-based instruction. These include the interdisciplinary and controversial nature of SSIs, a lack of familiarity regarding SSIs, the lack of necessary student skills, insufficient teacher expertise, and curriculum constraints. The PSTs viewed SSIs as able to potentially enhance their personal competencies through SSI-based instruction, mostly with regard to pedagogical skills. The relevance of SSI-based instruction was, however, not seen in as positive a light as the participants’ views on the need of character building. The PSTs’ intentions to later implementing SSI-based instruction ranged from medium to high.