Research in smooth muscle contraction has shown remarkable progress over the last 5 years. Striking advances have been made in the areas of biochemical regulation of contraction, centering on myosin light chain kinase activity, and of biophysical delineation of the contractile process at the actomyosin level by use of the newly developed motility assay. The purpose of the symposium held at Minaki, Ont., was to obtain a comprehensive reporting of the recent advances made in the area of smooth muscle contraction. Specifically, advances in the areas of biophysics of contraction, energetics, and contractile and regulator proteins (including the interesting newcomers caldesmon and calponin) and the changes that occur in pathophysiological entities such as asthma, hypertension, anaphylactic shock, high-altitude hypoxia, and persistent pulmonary hypertension of the newborn were presented.