The study was undertaken to establish whole blood mercury levels in the Saskatchewan population and to identify characteristics of individuals with higher blood levels. The mean blood mercury level was 6.7 ng/ml, the median level 5 ng/ml and the range 1 to 42 ng/ml. Native persons living in northern Saskatchewan who had recently eaten local fresh-water fish had the higher levels. A greater consumption of fish and higher blood mercury levels were recorded during the fresh-water fishing season.