This chapter examines the principles of integrated pest management (IPM). IPM often is defined as a program that, in the context of the environment and the population dynamics of pests, uses many different techniques and strategies in as compatible a manner as possible to maintain pest population levels below those causing economic injury. The concept of IPM was initially developed in traditional agriculture, where the success of a crop was measured in economic yield (quantity and quality of produce). The key to such agricultural IPM programs has always been establishing consistent and reliable “economic thresholds” — pest populations at which the cost of expected crop damage exceeds the cost of implementing control. In turf, the expected economic benefit from reducing a pest population usually is much more difficult to measure than in agriculture. It is difficult, if not impossible, to determine the economic value of suppressing pest insects. As a result, “economic thresholds” in turf IPM usually are more accurately described as “tolerance levels,” or “action thresholds.” In a turf IPM program, the turf manager must determine what pest populations can be tolerated without incurring unacceptable damage. The basic components of an IPM approach include assessing a site, monitoring and predicting pest activity, setting thresholds, managing turf stress, identifying and optimizing management options, and evaluating the results.