This lake supports an extremely diverse species complex that varies from basin to basin. Species known to be present include white perch, largemouth bass, yellow perch, chain pickerel, black crappie, pumpkinseed, bluegill, yellow bullhead, white sucker, golden shiner, American eel and several other species of panfish and baitfish. The lake is also stocked heavily with trout, usually rainbows, in both the spring and fall, and is stocked with broodstock salmon when they are available. In addition, the lake is stocked with northern pike and tiger muskies, and has consistently been one of the best fisheries in the state for these trophy species.

Few lakes in the Commonwealth offer as tremendous a variety of fishing opportunities as Lake Cochituate. Panfish are abundant in all basins, with the bluegill and yellow perch populations in particular containing plenty of big fish. American eels, many of them approximately a yard long, are also very abundant. Stocked trout provide good action throughout the year, and broodstock salmon are an additional bonus.

This lake supports an outstanding bass fishery. Bass research operations conducted in 1992 revealed good numbers of nice largemouths in all three basins, although they were most abundant in Middle Pond. Quality and trophy size northern pike are not uncommon, and there are certainly some legal size tiger muskies available. Ice fishing is a very popular and effective way to sample these outstanding fisheries.