This article reports findings of an empirical, field study of how virtual information systems development teams project managers improve team trust and cooperation by managing adaptation of information and communications tools. We examine the effect of leader style on the efficacy of interaction interventions. Results indicate how Theory X (command and control) and Theory Y (facilitate and support) leadership approaches enable and contradict effective technology adaptation, trust building, and outcomes. Successful technology adaptation led to increased trust. In order to achieve technology adaptation during interventions, leaders taking employing actions associated with a Theory Y approach achieved greater success. Implications for virtual project management are introduced.