One of the main reasons for imlementation of ISA 701 „Communicating key audit matters in the independent auditor's report“ is agency problem, because stakeholders are aware that external auditors possess much more informations about the audited entity then it can be seen in the auditors report, which represented one of the main disadvanteges in the previous audit report beacuse it was too standardised. „Key audit matters are those matters that, in the auditor’s professional judgment, were of most significance in the audit of the financial statements of the current period.“ Therefore, the main aim of this paper was to examine average number of key audit matters that are published in auditor report and to analyse the nature of key audit matters. Also, a fundamental contribution of this paper is to examine the relationship between the effectiveness of the audit committee members and the number of published key audit matters. The results of the research show that auditor report which contain only one key audit matter is most frequently disclosed, and in terms of the nature of key audit matters, the most common matters are revenue recognition, leases IFRS 16, assessment of useful life of property, plant and equipment and inventory impairment. Hypothesis testing found that audit committee effectiveness through index calculation doesn't have a statistically significant impact on the number of key audit matters. Throughout observing the impact of individual audit committee effectiveness characteristics (independence of audit committee members, cooperation of the audit committee with the external auditor) on the number of key audit matters, there hasn't been proven statistically significant impact of these variables and the existence of a negative relationship with the number of key audit matters.