We rst developed theory arguing that HR managers' and other middle managers' involvement during strategy making would have different effects on performance for rms pursuing different business-level strategies. Then, our empirical study tested the hypotheses in the context of HR managers and middle managers in the Hong Kong Special Administrative Region, People's Republic of China. We found that HR manager involvement during strategy making was positively related to perceptions of future business performance. The use of a differentiation strategy was also positively associated with future performance. Neither the use of a cost leadership strategy, however, nor involvement by other middle-level managers, was directly related to perceived future performance. Interestingly, pursuit of a cost leadership strategy, combined with either high HR manager involvement or high middle manager involvement, produced high business performance. Thus, we found a positive and signi cant interaction such that increasing levels of manager involvement in strategy and a cost leadership strategy was associated with much higher levels of performance. Lower levels of manager involvement combined with the cost leadership strategy, however, were related to much lower performance. No such interaction effect was apparent for differentiation strategies.