The subject of the paper is the operational risk in the banking system, and the aim of the paper is to present different theoretical approaches to the control and management of operational risk in banking and to present the operational risk situation in the banking system of Croatia and the world through analysis of available operational risk data. The basic hypothesis of the paper is that operational risks are integral part of banking business from day one and gone a long way from the lack of awareness of them until today when they are well-defined and well-known to everyone in the banking sector. For the sake of easier understanding of the methods, concepts and research, the basic theoretical terms used in the work were first theoretical explained, and then the practical part of the work followed. This paper presents a review of risk and risk definition, banking risk types, Basel agreements defining risks in banking and capital adequacy. More detailed breakdowns, types of operational risks, sources of operational risk, and ways of managing and measuring operational risks in banking. Finally, in the practical part of the paper, an analysis of the data on operational risks incurred in Croatia and the world was made based on operational risk loss data collected by the ORX Operations Risk Association for the period 2010-2015, published at the end of 2016. The paper confirmed the hypothesis that operational risks are integral part of banking business and has always been and will continue to be the biggest threat to banking risks in the coming years, as the development of technology that is increasingly being implemented in banks is constantly increasing its significance.