Freezing avoidance has been investigated in the cod, Gadus ogac, which inhabits the coastal waters of Labrador. The freezing point of the blood serum of fish collected from freezing seawater through the ice during the spring was -2.17 C, a temperature well below the freezing point of seawater. Antifreeze glycoproteins were isolated from the serum and shown to be responsible for half of the freezing-point depression of the blood. Chemical characterization of the glycoproteins indicated that they are the same as those present in the serum of the antarctic nototheniid fishes. The glycoproteins were found to be completely soluble in 40% trichloroacetic acid. This high solubility in trichloroacetic acid explains the previous observation of extremely high nitrogen concentrations in deproteinized G. ogac serum.