IWM is a part of integrated pest management (IPM) and adoption of IWM is an important driver for IPM. Within the project IWMPRAISE we developed a novel framework for integrating and implementing existing and novel approaches to IWM. Understanding the drivers of decision making by farmers are essential for a successful implementation of on farm IWM. In this chapter we review cognitive, social and dispositional factors often associated with the lack of IWM adoption by farmers: Lack of available knowledge on IWM; Limited evidence of efficiency, reliability and cost- effectiveness of IWM; Trade-offs with other parts of the cropping system; Increased complexity involved in IWM; Insufficient infrastructure to support relevant learning and decision making by farmers and land managers; individual values and beliefs of farmers affecting their attitudes to integrated weed management; Resistance to change and perception of risk. Finally, a framework for IWM decision making by farmers is presented.