Many organizations have started with the implementation of Information Technology Service Management (ITSM) in order to achieve the alignment between business and Information Technology (IT). ITSM is concerned with planning, sourcing, designing, implementing, operating, supporting and improving IT services that are appropriate to business needs. There are different concepts and standards for assessing the maturity of ITSM such as ITIL, ISO/IEC 20000-1, ISO/IEC 15504-8, CMMI-SVC. The goal of the paper is to analyze how specific IT service organization uses ITIL, ISO/IEC 20000-1 and CMMI-SVC standards for the measuring the level of quality of  the ITSM. The obtained results were compared in order to represent the actual quality level of ITSM in the IT organization.