The purpose of this study is to explore how pre-service science teachers’ awareness of alternative energy sources developed after participating in socioscientific issues-based (SSI-based) instruction focusing on alternative energy sources. This study was designed as a case study. The participants were selected by using the convenience sampling method and consisted of a total of 12 (10 female, two male) pre-service science teachers enrolling at a state university in Aydın province during the 2023-2024 academic year. The researchers designed an SSI-based alternative energy course. The data were collected by interviews using an alternative energy sources opinion form developed by the researchers before and after the SSI-based course. The results revealed that participants’ awareness of alternative energy sources was quite low, they were partially knowledgeable about the types, potential use of energy sources, and their potential to cover Türkiye’s energy demand before the instruction. The SSI-based course improved participants’ knowledge and awareness about the advantages and disadvantages of alternative energy sources.