The subject of this diploma paper is overtime work and it's legal treatment. The institute of overtime work retains a number of issues, from the very concept of overtime to how it is regulated, where does it appear and are there some limitations and responsibilities associated with it. The emphasis is on overtime work, but it is necessary to explain the working time institute, which involves working time types and time schedules. Also, it is very important to explain redistribution of overtime. Therefore, one of the basic aims of this work, through the subject matter of labor law and the provisions of the Labor Act regulating this matter, is to answer the above mentioned questions. The Labor Act prescribes restrictions on the introoduction of overtime work with the aim of excluding it as an exception in case of extraordinary circumstances. It can be used in the event of force majeure, extraordinary increase in the scope of work, and in other cases where there is a need for a worker to work longer than full – time on na written request of an employer. It is actually about situations that are unpredictable and which the employer could not avoid, and when such situations occur, the employer orders overtime work to the worker and he is obliged to do it, otherwise it constitutes a serious breach that leads to an exceptional dismissal of the employment contract. Finally, a few examples from the jurisprudence of the courts in the Republic of Croatia are given to illustrate the application of overtime work in more detail.