A very important issue for business management is how well Information Systems (IS) strategy is supporting its business strategy and direction, in the current and future business and information technology (IT) circumstances. The issue of monitoring, reviewing and maintenance of IS strategies from a strategic perspective, (strategic IS control), have enjoyed little attention by IS researchers in the past. The paper reports on a study to investigate current strategic IS control practices in New Zealand and to measure their level of effectiveness. A field survey of 123 New Zealand organisations provided the data for the study. The results show about 80% of NZ organisations practising IS planning also practise strategic oriented control over their strategic IS plans one way or another, and with varying degrees of effectiveness. Also, strategic IS control is found to significantly influence the performance of the strategic IS plan. In addition to increasing our understanding of the issue of strategic IS control and its current approaches, the significance of the study is two folds. First, the study proves the fact that strategic IS control impacts IS plan performance, and second, it provides a criteria that help IS practitioners to evaluate and set up their strategic IS control systems.