The globalization of the economy and the levelling of the boundaries in entrepreneurial activity necessitates the international comparability of corporate financial reports in order to make effective management decisions by banks, business partners, rating agencies and other. The article addresses possible changes in company's creditworthiness, represented by the change in the achieved values of the Z-score bankruptcy model as a result of data application from the IFRS financial statements as compared to the data from the reports compiled according to the Czech Accounting Standards. The intention has been to highlight the possible deterioration in its creditworthiness. This article aims at mapping out the differences between the two modifications in the area of acquisition and valuation of fixed assets in the selected segment of construction companies and demonstration of their impact on the explanatory power of financial statements prepared in accordance with the Czech Accounting Standards and IFRS. The article also identifies the risks that this situation brings to users of accounting statements. When using the data of 20 financial statements of entities with main activity in the construction sector lower values were achieved for the Z-score indicators compiled from the IFRS statements as compared to the values determined with the use of data from financial statements prepared according to the Czech Accounting Standards. The main reasons for this impact are the differences in the procedures for discounting of assets values to present value and accounting for the lease which may lead to significant differences in the financial performance of the company, levels of its financial stability and market value. It is proved that these differences can have a certain risk for the portfolio of companies credited by one bank.