Interest in pesticide residues in foods has increased, and the issue of residues in imported foods has been raised as a potential public health problem. Three U.S. government agencies, EPA, FDA, and USDA, are responsible for regulating pesticides. EPA sets tolerances, and FDA and USDA enforce those tolerances. As part of its regulatory activities, FDA conducts a regulatory monitoring program that samples and analyzes each year approximately 20,000 food shipments, about 60% of which are imports. Samples of imported foods are collected at ports of entry, and are chosen on the basis of several factors rather than on a completely random basis. Raw agricultural products are emphasized. Most analyses are performed using MRMs, to make best use of FDA's resources. Using five MRMs, about half of the 300 pesticides with U.S. tolerances can be determined. Results from monitoring over the past several years have shown that nearly 60% of the imported foods sampled had no pesticide residues detected. Of those samples that were violative, 5% contained residues for which there was no U.S. tolerance, and less than 1% had over-tolerance residues. Examples are given of the various pesticide/commodity combinations that have been found to be violative. FDA is often criticized for the scope of its pesticide coverage, particularly with regard to imported foods. Some critics have promoted the idea of a 'circle of poison,' which is based on the premise that pesticides banned in the U.S. are exported and used on foods in foreign countries; then the food containing these residues is imported into the U.S. and consumed. However, FDA's testing of imported foods has shown that residues of EPA-banned pesticides are not occurring from currently purposeful uses. The violation rates for imports also have not been significantly different from those for domestic foods. This indicates that foreign producers, as well as domestic growers, generally use pesticides in a manner consistent with EPA requirements. FDA continues to broaden its information-gathering capabilities. As mandated by the PMIA of 1988, FDA will attempt to obtain pesticide use information from countries that are major food exporters to the United States. An improved data management system will also be in place, and a long-range analytical method development plan instituted. Several international organizations address the issue of pesticide residues in foods. Attempts at harmonization of national tolerances for pesticide residues have not been successful, i.e., a number of individual nations have not accepted Codex MRLs.(ABSTRACT TRUNCATED AT 400 WORDS)