A study of anadromous sea lampreys (Petromyzon marinus) at Love Lake, Washington County, Maine, provided evidence that newly transformed lampreys were attaching themselves and in many instances feeding upon landlocked salmon and other fishes. Examination of 660 salmon from 4.5 to 23.5 inches long revealed that 564 (85%) had been attacked by newly transformed sea lampreys. Salmon were attacked more frequently than all other species combined. The greatest number of lamprey marks observed on any one salmon was eight, and the average number on salmon that has been attacked was 2.4.