The present study aimed to investigate pre-service elementary teachers' development and use of worksheets for science and technology course, and to obtain their opinions about these applications. To fulfill this end, in the study, it was employed the case study model as a qualitative research model. The applications were conducted during the fall and spring semesters of the academic year 2008-2009 in the Faculty of Education at Celal Bayar University. The study data were collected through the worksheets prepared by the pre-service teachers as a result of the applications, an opinion form, and semi-structured interviews. The presentation files prepared by the pre-service elementary teachers were examined through document analysis. Furthermore, the data obtained through the opinion form were examined by content analysis, while the data from the semi-structured interviews were analyzed by the descriptive analysis method. The results of the study revealed that the pre-service teachers usually prepared and used worksheets for the purposes of assessment, identification of previous knowledge, activity development and in the form of experiment/activity reports. As for the acquisitions of the use of worksheets, the pre-service teachers mentioned their contributions such as identifying learning levels, revealing previous knowledge, providing experience, teaching preparation and increasing interest in the course. Moreover, most of the participants stated that they had certain problems about choosing suitable questions, and developing questions appropriate for students' levels while developing worksheets. In the light of these results, certain suggestions are made about the preparation and use of worksheets.