The aim of this study is to reveal opinions and experiences of two Computer Education and Instructional Technologies Departments' students about case study discussion method after they discussed in online asynchronous environment about Instructional Design (ID). Totally, 80 second year students, 40 from Dokuz Eylul University and 40 from Karadeniz Technical University, participated to the study. Communication among students was managed via discussion lists. The data were collected with questionnaire, written reports, observations and interviews. The findings indicated that this learning environment made a positive effect on ID knowledge of students. In addition, students stated limitations and positive results of discussing in asynchronous learning environment. Lastly, students suggested some opinions to make this environment more efficient and effective.