It is important to support pre-service teachers in terms of mathematical task design so as to increase the success of their future teaching. The purpose of this study was to evaluate mathematical tasks designed by pre-service primary and elementary mathematics teachers within the framework of task design principles. For this purpose, a total of 43 tasks corresponding to the learning objectives in primary and elementary school mathematics curriculum were examined through content analysis. Results revealed that pre-service teachers have considered aim of task, classroom organization, students' prior knowledge and multiple start point principles for all or most of their tasks; measurement and evaluation principle for almost half of their task; and instruction for using materials and student's misconceptions and difficulties principles for very few of their tasks. This study can provide teacher educators with a guideline for improving their programs to support pre-service teachers in terms of mathematical task design.