Freshwater suckers (Catostomus spp.) were harvested from Lakes Huron, Michigan, and Superior during different seasons of the year. Initial compositional analyses and storage stability of products held at −18 °C for periods of 1, 3, 6, and 12 mo were determined for coarsely ground (eviscerated) fish, minced flesh, and loin and belly flap muscles. Moisture levels ranged from 75.3 to 83.5%, showing no consistent differences among lakes, harvest dates, or fish portions. Calcium levels of minced flesh averaged 0.08%, only about one tenth of that from coarsely ground fish. Lipid analyses (2-thiobarbituric acid test, TBA) showed increased lipid oxidation with storage time. Those results indicate that untreated minced flesh may be stored frozen for at least 6 mo without serious lipid oxidation, since TBA numbers averaged < 2.0 at that storage time. Lipids in loin muscle were least oxidized, followed by minced flesh, belly flap, and coarsely ground fish, respectively. Key words: fish, mechanically deboned, storage stability, sucker, lipid oxidation