We documented predation on smolts of Atlantic salmon (Salmo salar) by striped bass(Morone saxatilis) foraging in the tailrace of the Essex Dam on the Merrimack River, Lawrence,Massachusetts, and assessed factors that may affect smolt susceptibility to predation. During 6 dof diurnal angling from 6 to 28 May, we captured 212 striped bass, 41 of which contained preyremains. More than 48% of striped bass that contained prey had consumed smolts. Atlanticsalmon smolts composed more than 80% of the total mass of prey remains recovered andincluded both individuals of stocked-fry and stocked-smolt origin. Based on information from thispilot study, a focused investigation of striped bass predation on smolts after passage of the EssexDam began in 1998.