The research problem is the entire process of introducing the new IFRS 9, which replaced the previous IAS 39, on the example of Croatian credit institutions with emphasis on comprehensive analysis and description of the procedure for replacing IAS 39 with IFRS 9 and its impact on business institutions for business year of 2018. The main goal of this research is to show the effect of the new IFRS 9 in relation to IAS 39, on the example of credit institutions, highlight the new elements introduced by IFRS 9 and how they were implemented, and describe and empirically support the results of analysis of financial statements institution with the consequences of the introduction of IFRS 9 as well as possible future financial trends that it carries. The results of the initial application of IFRS 9 in 2018 show a negative effect on the overall banking system, ie how there is a correlation between the introduction of IFRS 9 and the business success of the banking system. Despite the appearance of negative results, the new Sandard showed significant improvement compared with IAS 39. IFRS 9 changed the way financial assets are classified and measured, credit losses are easier to identify, full transparency and objectivity of data that ultimately reflected on improving the stability of credit system.