Ethyl formate (EF) in combination with CO₂ was tested for control of arthropods commonly infesting California table grapes. In addition, table grape tolerance to EF exposure was evaluated. LC₉₉ estimates were developed for target pests by using a range of EF concentrations (0.04–4.7% EF). Response to treatments varied greatly between species, as well as life stages within species. Western flower thrips, Frankliniella occidentalis (Pergande), and adult and crawler stages of grape mealybug, Pseudococcus maritimus (Ehrhorn), were most susceptible to EF treatments. Least susceptible were grape mealybug eggs; Pacific spider mite, Tetranychus pacificus McGregor; and omnivorous leafroller, Platynota stultana Walsingham. The LC₉₉ for target pests fell within the range of EF concentrations tolerated by table grapes with the exception of 1-, 3-, and 5-d-old omnivorous leafroller pupae.