In order to prescribe procedures for companies to measure their assets (IASC 2000), this study investigates the influence of the Impairment of Assets Standard affecting shareholders investing in Resources, Industrials and Property and Construction listed companies in Thailand. This study is expected to discover the effect of the relevant figure in the income statement and net profit and earnings per share on which individual shareholders rely to make informed decisions. This is a significant issue in listed companies that are large asset-based industries. The present study examines companies in: Resources; Industrials; and Property and Construction that represent 53 percent of the market capitalisation of listed companies in the Stock Exchange of Thailand (SET). The auditors recommended that clients set up provisions for any impairment of asset loss (Srijunpetch 2004) after the accounting standard Impairment of Assets (IAS 36) was revised in 2004. Moreover, this study also investigates the point of view of individual shareholders when making informed decisions, rather than the point of view adopted by the preparers of financial information or the standard setters.