ELISA techniques were used to detect imidacloprid in guttation fluid of young cantaloupe plants in Arizona. Imidacloprid was detected at up to 4.1 µg/ml (ppm) in a coincidental guttation collection 3 d after a top label rate soil application and at 37 µg/ml one d after a separate top label rate soil application study. These imidacloprid titers exceed reported median oral toxicities for several insect species by factors of 10 or more. Pesticides in guttation fluid are a relatively unexplored route of exposure for both pest and beneficial insects, and could represent an important risk for both of these groups in guttation-prone environments.