The violation of a contractual obligation or other obligation arising from the employment relationship is defined as a legitimate reason for ordinary cancellation of an employment contract. The employer can cancel an employment contract according to the procedure defined in Article 85 and Article 89 ZDR-1, as well as specifying the correct reason for cancellation, otherwise cancellation is illegal. Based on the third paragraph of Article 200 ZDR-1, the worker has a right to take legal action within 30 days from the date of service of notice of cancellation. The position of the judicial practice is that each violation made by a worker does not automatically represent substantiated reason of misconduct; even the violation represents a resignation from expected behavior of the worker. The cancellation of an employment contract is illegal if it is possible to deal with the violations in the context of the normal work process and if the violation is done by a reliable worker. The courts consider all factual and legal circumstances of an individual case to verify if reason of misconduct was justified. Case law in the aspect of the cancelation of employment contract by reason of misconduct is relatively transparent and well-developed. Therefore, before the beginning of court proceedings, it is rational that worker and the employer look for relevant case law about the issue in dispute. This way they may also avoid the unnecessary legal costs.