The purpose of this study was to evaluate pre-service science teachers' argumentation skills, attitudes and knowledge levels regarding organ transplantation and donation (OTD). Teachers play a fundamental role in providing information to children/adolescents and could influence their attitudes. Organ transplantation is a life-saving hope for many people, but shortage of organs for transplantation is a universal problem. Having a positive attitude and true knowledge are essential for teachers that affect students' future attitude toward this topic. The research method was descriptive and cross-sectional. The sample of research was 472 pre-service science teachers, who were sampled by using convenient sampling method and are students of Science Education Department at four different public universities. Data collection instruments were developed by researchers as valid and reliable questionnaire in order to determine the attitudes, knowledge levels and argumentation skills of pre-service teachers regarding OTD. Results observed that the pre-service science teachers' argumentation skills in a socio-scientific subject such as OTD were at a very low level, their attitudes were at a moderate level, and their knowledge level was above the average. Results of the study have shown that graduated high school type and grade level have played important roles in the positive attitudes, high argumentation skills and high knowledge level about organ donation. No significant difference was found in the attitudes and knowledge level of pre-service science teachers toward OTD in terms of gender. The gender only affected the ability of argumentation.