The present text focuses on selected issues with regards to the private law principle of the autonomy of will and its manifestations within the area of labor law. More precisely, its limitations are analysed in the event of concluding an employment law relationship for a fixed term. The major restriction in the given context is seen in the requirement of one of the contracting parties to be procedurally active (while performing the respective juridical act) so that the anticipated legal consequences could be achieved. Firstly, the following paragraphs briefly deal with the general position of Czech labor law within the national regulation, in order to introduce the relevant legal context. Secondly, the main scope of the text represents limited analysis of a current fixed-term employment law relationship regulation from both the national (Czech) and supranational (EU) perspectives. Most importantly, the respective provisions arising out of applicable laws on the domestic level (the Czech Labor Code) have been confronted with those existing on the EU level (Directive 99/70/EC). Therefore, the desirable accordance of the former with the latter could be proven. As far as no less significant practical aspects are concerned, the final part points out actual challenges related to presupposed legal conversion of a fixed-term employment law relationship (based on the concluded employment contract) into an indefinite one. In the light of recent case law which will be mentioned, the conditions as prescribed in the Czech Labor Code are not interpreted unanimously, which naturally affects its application in practice in a more negative manner.