Assessing the efficacy of technical communication service courses is a complex task, yet it is a task that service course providers should embrace as an opportunity to learn more about student and faculty needs and to update and improve curricula. This assessment has become more immediate for many educators because of ABET 2000 (Accreditation Board for Engineering and Technology), a comprehensive revamping of the way engineering programs are accredited. ABET 2000 criteria require that engineering programs provide evidence of the efficacy of all instruction, including communication. When the new ABET criteria were released, we had already begun a comprehensive evaluation of not only our service courses but also the total writing experience of engineering students at the University of Washington. This paper gives a theoretical rationale for a portfolio evaluation project and describes a directly applicable structure and procedure for such a project.