While some progress has been made in recent years to treat property as part of the wider capital markets, the subject of indices largely remains poorly understood by the surveying profession even though they play a central role in investment management. Commercial property indices therefore continue to generate confusion both inside and outside the property industry. Reviewing the characteristic features of property, outlines the conceptual and practical problems faced when constructing property indices which are not encountered in other markets. These have major implications for index producers and users alike. Reports on a recent study undertaken by the Society of Property Researchers. Although significant progress has been made in recent years towards the provision of more reliable UK property performance data, further improvements are recommended if property indices are to command a level of respect comparable with that enjoyed by indices of other markets.