The IT integration of acquisitions consists an important challenge for the many acquiring organizations. Complementing existing research, this paper searches for explanation to differences in acquirers’ abilities for acquisition IT integration in the external of the acquirer, by a study of the use of temporary agency workers. Following an analytic induction approach, theoretically grounded in the re-source-based view of the firm, we identify the complimentary and supplementary roles consultants can assume in acquisition IT integration. Through case studies of three acquirers, we investigate how the acquirers appropriate the use of agency workers as part of its acquisition strategy. For the investigated acquirers, assigning roles to agency workers is contingent on balancing the needs of knowledge induction and knowledge retention, as well as experience richness and in-depth under-standing. Composition of the acquisition IT integration team should consider the balance of these, in practice, commonly mutually excluding needs.