The importance of chemical stimuli in longlining was investigated by comparing the catching power of baits soaked in sea water prior to baiting with that of fresh bait in fishing trials for torsk ( Brosme brosme). Mackerel baits presoaked for 2, 4 and 24 h gave 87%, 84% and 50% of the catch rate of fresh bait, respectively. The results are discussed in relation to data on temporal change in release rate of feeding attractants from bait and the sensitivity of the chemical senses in fish. It is concluded that for bottom set longlines, high release rate of attractants is of great importance to attract fish to the gear, whereas fish present close to the gear during setting may also respond to the baited hooks by visual stimuli.