This volume contains the edited proceedings of a workshop conference, THE SMOOTH MUSCLE OF THE ARTERIAL WALL, held at Max Planck Haus, Heidelberg, West Germany, on the occasion of the dedication of the new Myocardial Infarct Institute of the Univer­ sity of Heidelberg. The conference was a sequel to one held three years earlier at Lindau, West Germany, on THE ARTERY AND THE PROCESS OF ARTERIO­ SCLEROSIS. The earlier conference examined available data and conflicting theories on the pathogenesis of arteriosclerosis. A major yield of this gathering was a consensus that smooth muscle cell proliferation in the sub-endothelial space is a fundamental feature of atherogenesis. It was, therefore, decided in a second conference to bring together existing knowledge of arterial smooth muscle and of the structure and function of smooth muscle in general. Accordingly an international and interdisciplinary group of experts were gathered together to assess current knowledge, to attempt reconciliation of disparate data and synthesis of widely scattered information and to identify critical areas of ignorance. As before, the conference was conducted in the form of a dialogue with only a minimal number of formal presentations. Grateful acknowledgement for financial support of the confer­ ence is extended to: The Government of Baden-Wurttemberg, West Germany The Marine Biomedical Institute of the University of Texas Medical Branch, Galveston, Texas The Office of Naval Research, Washington, D.C.