Concentrations of the trace elements iron, cobalt, nickel, copper, zinc, cadmium, and lead were measured in samples collected from the waters of the Gulf of St. Lawrence. Cobalt, cadmium, and lead occurred at or below the detection limits of the analytical method. The mean concentrations of nickel, copper, and zinc were 0.4 μgl−1. 0.6 μgl−1 and 1.8 μgl−1 respectively, and there was no evidence that local conditions influence their distribution. The distribution of dissolved and colloidal iron is related to dilution and precipitation processes which occur as fresh and saline waters are mixed. The particulate iron distribution is largely governed by water circulation patterns and settling.