The twospotted spider mite, Tetranychus urticae, is a common pest of tomatoes in the piedmont and mountains of North Carolina. Growers rely almost exclusively on chemicals for management of mites therefore acaricide resistance development is a serious concern. Studies were conducted to establish action threshold levels for twospotted spider mite on staked tomatoes to lead to the more judicious use of acaricides. Two different plantings of tomatoes were established with spider mite infested transplants. Five different mite threshold levels (0, 1, 25, and 50 mites per leaflet and an untreated control) were randomly assigned to an early and late planting of tomatoes. Terminal leaflets were examined at weekly intervals, and upon reaching the respective thresholds, acaricide applications were made. Fruit was harvested from six plants as vine-ripe fruit, then weighed and graded according to USDA standards. An economic analysis was performed to estimate a threshold level to dictate the need for acaricide use.