The purpose of the current study is to explicitly test the extent to which issue contexts affect the informal reasoning processes engaged in by individuals. In order to address the research question framing this study, we engaged 39 Turkish preservice science teachers (PSTs) in interviews designed to elicit argumentation related to multiple socioscientific scenarios. Three scenarios related to gene therapy, another three related to human cloning, and the final scenario related to global warming. The data were analyzed using an interpretive qualitative research approach. Our work builds on a framework initially proposed by Toulmin in 1958. This study has provided new evidence related to informal reasoning in the context of socioscientific issues (SSI). At the sample level, there was strong consistency in informal reasoning quality among varying socioscientific scenarios. However, finer-grained analyses indicated a greater level of variability in the informal reasoning practices of individual PSTs. These results support previous conclusions that suggest context dependence for informal reasoning related to SSI. This study provides an initial picture of the reasoning practices of preservice teachers as opposed to science learners. The results indicate that teachers, at least those in this Turkish setting, would benefit from learning experiences that support their own informal reasoning practices as well as their ability to foster development of these practices among their students. We encourage the field to continue the investigation of SSI as contexts for education particularly as it relates to the education of teachers. (Contains 3 tables and 1 figure.)