During a comprehensive total diet study extending from 1985 to 1988, foods were collected in 6 Canadian cities (in one of them, a pilot study was conducted twice). For each of the 7 collections, foods were processed into 112 composites (105 in the initial pilot trial). Total arsenic was determined in all samples. The mean, median, and range of arsenic concentrations in all samples were 73.2, 5.1, and < 0.1-4830 ng/g, respectively. Food groups containing the highest mean arsenic levels were fish (1662 ng/g), meat and poultry (24.3 ng/g), bakery goods and cereals (24.5 ng/g), and fats and oils (19.0 ng/g). The estimated daily dietary ingestion of total arsenic by the average Canadian was 38.1 micrograms and varied from 14.9 micrograms for the 1- to 4-year-old group to 59.2 micrograms for 20- to 39-year-old males.