The topic of this thesis is long-term intangible assets. This Work explains on a theoretical and practical example the importance of long-term intangible assets in the operations of companies from different industries and the impact on the value of companies. At the beginning of this thesis, the subject, purpose, goal, research methods and structure of the thesis are defined. Furthermore, the concept of long-term intangible assets and their types are defined as accounting regulations through International Financial Reporting Standard 38 and Croatian Financial Reporting Standard 5. The third chapter explains the accounting monitoring and tax treatment of long-term intangible assets and methods of acquisition, disposal and use of long-term intangible assets and tax treatment of the same. Chapter 5 defines the methods of valuing long-term intangible assets according to International Financial Reporting Standards and Croatian Financial Reporting Standards. The last part of this thesis shows on practical examples the importance of long-term intangible assets in the food, information technology and pharmaceutical industries. Selected companies from each industry are Podravka d.d., Nanobit d.o.o. and Pliva d.d. Through a detailed analysis of the structure of assets and the share of intangible assets, the impact on the value of the company is defined. The result of the analysis shows that only in the information technology industry, long-term intangible assets have a great impact on the value of the company.