Conceiving, designing, implementing, and operating (CDIO) is one of the most novel and recent approaches for engineering education. Stressing on active learning as the major instructional tool, it purports to deliver technical knowledge as well as communication and professional skills to engineering students. This paper describes how CDIO principles were used to partially revise design courses in our mechanical engineering program. Two mid-level courses, Creative Design and Machine Design, are presented as case studies. CDIO driven changes in course objectives, instructional strategy, and assessment tools are presented, incorporating active learning elements such as problem-based learning, group learning, and project-based learning. Student groups are required to convert their completed design ideas into an actual product, considering societal, economic, and environmental factors; test the product, and evaluate the challenges and issues. Initial surveys show good response in terms of acceptance and enthusiasm, though both faculty members and students are a little apprehensive about the possible extra workload. The strategy described in this paper is expected to be beneficial for faculty and students in design related courses in particular, and in other engineering and science courses.