To date, aneurysm research has been primarily descriptive, reiterating the complex nature of the disease process. Enhanced by the convergence of matrix biochemistry, cell biology and immunology, this work is providing important new insight into how matrix metabolism is regulated in the diseased aorta. The focus is now on the inflammatory process and its regulation of the matrix remodeling which occurs with abdominal aortic aneurysm. A family of matrix-degrading enzymes appear to have a central role in this process. As we have learned from the evolution of the treatment of other pathologic processes such as peptic ulcer disease, the most effective pharmacologic therapies are designed from a thorough understanding of the pathophysiology of the disease. We are quickly moving forward in formulating a comprehensive understanding of the various complex interactions that result in the formation of aortic aneurysm. Given the progress of the past decade, we can expect the identification of aneurysm-associated genes and clinical trials of anti-inflammatory medications and protease inhibitors as we enter the 21st century.