The study aims to determine the effect of socioscientific issues-based activities on the attitudes of primary school teacher candidates' about life science teaching. In this research, 78 primary school teacher candidates (52 females, 26 male) determined by criterion sampling method participated. Attitude Scale of Life Science Teaching was used as pre-and post-test. While the courses with the teacher candidates in the control group were given based on the curriculum determined by the Council of Higher Education (YÖK), the experimental group teacher candidates held socioscientific discussion activities for eight weeks. The difference between the pre-and post-test mean scores of the primary school teacher candidates in the experimental and control groups was analyzed using the dependent and independent groups t-tests. The effect size was calculated (eta squared (n2)) according to the variances between the scores. As a result of the research, it was determined that the difference between the pre-test and post-test average scores of the primary school teacher candidates in the experimental and control groups on life science teaching attitudes was not statistically significant. However, a statistically significant difference was found between the experimental group mean scores of their attitudes about life science teaching before and after the socioscientific issues-based discussion activities. The effect size (n2) of the difference between pre-test and post-test mean scores was calculated as moderate. Socioscientific issues-based teaching activities, which are mostly used in researches on science courses, were used by the researcher in terms of life science teaching in this study.