We report on the food of breeding Great White Egrets (Ardea alba) in an agricultural ecosystem in southern Chile, South America. Analysis of diet was based on prey remains and pellets collected under the nesting trees during the reproductive season. Pellets indicated that insects were the most numerous prey items (78%), followed by the Southern Crayfish (Samastacus spinifrons) (21%). The Southern Crayfish accounted for 92% of the biomass. In terms of prey remains, the Southern Crayfish was the primary prey item accounting for 97% in frequency and 98% of the biomass. When pellets and prey remains were combined, the Southern Crayfish remained the most numerous prey item (67%), followed by insects (32%). The other prey items constituted less than 1%. Significant differences were found between the diets estimated by the two methods. We suggest that results of pellets and prey remains should be combined to evaluate the diet of the Great White Egret. Significantly, more crustaceans and fewer insects were consumed during the late part compared with the early part of the breeding period, and differences were found amongst the orders of insects taken in the same periods. The food of the Great White Egrets is influenced both by spatial availability patterns and profitability of prey type.