Observations on host plant selection in a pentatomid bug, Eurydema pulchrum Westwood were made using olfactometer techniques. The response of the bug to different plant species such as Brassica oleracea, Raphanus sativus and Solanum lycopersium in different forms (intact plant/macerated) and different varieties of B. oleracea (B. o. capitata/B. o. botrytis) has been shown. The results indicated that secondary metabolites present in B. oleracea play an important role in selection of host plant by the bug.