Physical and hydraulic characteristics of upstream fish passage structures (e.g., fishways, fish lifts) are critical for effective attraction and entry of target species to be passed. These characteristics may be species specific, but have not been extensively quantified. We evaluated attraction and entry of adult American shad and lake sturgeon to experimental surface and submerged orifice entrance structures at several entrance head differential (water velocity) and siting (center of channel, side of channel) conditions, under controlled laboratory conditions. Initial attraction of American shad to both entrance types was relatively rapid under all conditions and was highest for the lowest test entrance velocity . For surface weirs, attraction rate appeared to decrease with increasing head differential. American shad entered surface weirs preferentially over orifices; head differential appeared to have no effect on orifice attraction rate of American shad. Lake sturgeon appeared to be more attracted to surface weirs than orifices at the lowest head differential; attraction to orifices and surface weirs at the higher head differential was roughly equivalent. Sturgeon appeared to display no preference for entry via surface weirs or orifices, but overall proportion of fish passing was low, which may have limited statistical precision of results. Both species appeared to show little preference for either center or side entrances, except that American shad strongly selected the side surface weir at the 0.30 m differential. Results from this study show a degree of interplay between attraction and passage for various entrance configurations and hydraulic conditions. Depending on species, one particular combination of factors may elicit strong attraction, but only modest passage.