Cell adhesion assays for drug discovery and drug safety analysis are often carried out as high throughput studies using microtiter plates. These assays are sufficient for basic studies but do not take into account the physiological shear flow conditions that are present in vivo. Examples include blood vessels where the presence of shear flow may influence compound effectiveness and the stability or functionality of molecular interactions involved in cell adhesion. To provide maxi- mum physiological relevance for HCA, we have developed a system which provides arrays of microfluidic flow cells coupled to standard well plate formats. These microwell plates run live cell assays under controlled shear flow and are compat- ible with bottom-reading imaging modalities like inverted microscopy and HCA imaging systems. We have demonstrated a number of image-based assays such as evaluation of VLA-4 inhibitors of adhesion to rhVCAM-1 under flow and evalu- ation of GPIIb/IIIa inhibitors of platelet adhesion under high shear. We have also demonstrated the successful use of commercially available cell HCA staining systems, including the CellCiphr and Neurite outgrowth kits (Millipore).