In 2015, the International Agency for Research on Cancer1 classified 3 pesticides frequently used in agriculture—glyphosate, malathion, and diazinon—as carcinogenic to humans (group 2A) based on evidence from studies of occupational exposure in humans and laboratory studies in animals. Through occupational exposure (primarily in agricultural settings), malathion is associated with prostate cancer, diazinon is associated with lung cancer, and all 3 pesticides are individually linked to non-Hodgkin lymphoma.1 In the general population, low-level pesticide exposure is widespread, and the primary route of exposure is diet, especially intake of conventionally grown fruits and vegetables.2 In the United States, more than 90% of the population have detectable pesticides in their urine and blood.3 Organic foods are produced without synthetic pesticides and are less likely to contain pesticide residues than conventionally produced, nonorganic foods.4 Crossover trials have shown that switching from consuming conventionally grown foods to organic foods decreases urinary concentrations of pesticide metabolites, suggesting reduced exposure to pesticides.4 Nevertheless, the health consequences of consuming pesticide residues from conventionally grown foods are unknown, as are the effects of choosing organic foods or conventionally grown foods known to have fewer pesticide residues.