Enterprise risk management (ERM)has recently emerged as a widespread practice in financial institutions. It has been increasingly codified and encrypted into regulatory, corporate blueprints, A burgeoning literature of regula governance and organizational management tory and practitioner texts is indicative of the apparent diversity of ambitions. objectives and techniques that constitute the ERM agenda. Making sense of these developments is a organizations challenge. This paper presents field-based evidence from two large banking suggesting that systematic variations in ERM practices exist in the financial services industry. The cases illustrate four risk management ideal types and show how they form the risk management mix in a given organization. Further, drawing on the literature ofthe roles and uses of management control systems (MCS), the paper explores how ERM achieved organizational significance in the studied settings. The findings are indicative of the current co-existence of alternative models of ERM. In particular, two types of ERM models are postulated: one driven by a strong shareholder value imperative (ERM by the numbers), the other corresponding to the demands ofthe risk-based internal control imperative (holistic ERM). This paper explains the differences in the two risk management mixes pointing towards alternative logics of calculation [Power, M.K 2007. organized Uncertainty-Designing a World of Risk Management. describe as different calculative oxford University Press, oxford which I conceptualise and cultures.The study suggests that calculative which in these cases shaped managerial predilections towards ERM practices, are relevant, albeit so far neglected, constituents o the fit between Mcs and organizational contexts 2008 Elsevier Ltd. All rights reserved.