Quality assurance in engineering education plays an increasingly important role in cultivating engineering talents around the world. The ABET EC2000 reform, in particular, has had a range of different impacts on U.S. universities and colleges as they work to meet accreditation standards. For example, large research-oriented universities with strong quality assurance cultures may pay more attention to setting up internal quality assurance systems at multiple levels. It is necessary to explore and discuss how such universities establish their own internal quality assurance mechanisms to continuously promote quality improvement, while also meeting accreditation requirements. This paper uses Purdue University as a case study of these processes. As valuable background information, relevant global literatures on quality assurance in engineering education are first reviewed in this paper. Then, the quality assurance mechanisms in engineering education at Purdue University are then more deeply analyzed and presented based on data from interviews with ten key stakeholders involved with ABET accreditation at Purdue University. The stakeholders were interviewed using a semi-structured protocol which elicited their concrete experiences of preparing for ABET accreditation as well as their attitudes towards quality assurance in engineering education. All stakeholders were also asked to share their views about other internal quality assurance mechanisms and current efforts to assure the quality of engineering education. The interviews were systematically analyzed using qualitative coding procedures, including inductive and deductive coding. This paper finds that Purdue University, as a research-oriented university, has set up a relatively integrated internal quality assurance system of engineering education which includes at least two types of mechanisms: organizational mechanism both at the university level and the college/departmental level, evaluation mechanism of coping with ABET accreditation and evaluation mechanism of teaching and learning to facilitate daily management.