The behaviour of cyprinids belonging to different ecology groups (rheophilous, eurytopic) were observed below a weir that was restricting their upstream migrations during the spawning period May? July. Positions of chub Leuciscus cephalus (L.), Prussiancarp Carrasius auratus gibelio (Bloch 1783), bream Abramis brama (L.) and white bream Blicca bjoerkna (L.) were recorded using an automatic data logger (ALS) in the upper Elbe River, Czech Republic. For all observed species, two activity peaks occurred;however, the interspecies timing of these peaks differed. Peak times for chub, bream and white bream occurred at night and during daylight, whereas Prussian carp was active mostly at night. Specimens of the rheophilous group suggested more efficient behavioural tactics in passing the weir than did eurytopic species.