In this report, the issues discussed at a multidisciplinary symposium on blood flow in bifurcations are summarized. Topics adressed are (1) flow analysis in vitro models, using visualization and laser Doppler anemometer techniques, and numerical models; (2) the influence of (physiological) factors, such as vessel wall distensibility and vessel geometry, on the flow field; (3) the noninvasive assessment of arterial wall properties in humans, and (4) the noninvasive determination of flow patterns in humans, paying special attention to ultrasound techniques and magnetic resonance imaging. It was empasized that it is of utmost importance to obtain more detailed information, preferably three-dimensional, about flow field in bifurcations, not only from a diagnostic point of view but also to get more insight into the relation, if any, in between flow patterns and atheregenesis. It was agreed that plaque geometry and dynamics should be studied in more detail, especially in relation to plaque fissuring and rupturing. There is a need for the noninvasive assessment of wall shear rate and, hence, to be able to calculate wall shear stress, because these parameters have been shown to be important determinants of endothelial cell function.