Spiders were studied as predators of the invertebrate epigeic fauna inhabiting forest and grassland ecosystems variously polluted with metals. The response of detoxifying enzymes in adult male and female spiders (a wolf spider Pardosa lugubris and a funnel weaver Agelena labyrinthica) was compared using material collected at five sites in forest and grassland transects along the metal pollution gradient. Carboxylesterases, acetylcholinesterase and metal concentrations were assayed in spiders during the season. In both species at the most polluted sites of forest and meadow transects CarE activity was higher. These animals effectively used quantitative compensatory strategy against pollutants, which demands extra energy. Comparisons between species showed a better adaptation to pollutants in the ground wolf spiders. In these animals from polluted meadows AChE activity was also higher than that in agelenids.