The occurrence of errors in public works tender documentation is an undesirable phenomenon which is unfortunately often encountered in construction practice. Errors may have various causes and also have varying levels of negative effects on the successful implementation of the investment project. Taking this fact into consideration, this paper aims to identify and assess errors in terms of the requirements laid down by the applicable legislation in the Czech Republic, especially the Public Procurement Act and the associated implementing decree. A total of 126 public tenders were analysed in detail from this perspective. The results show that the occurrence of particular errors is relatively high, especially with regard to the specification of the bill of quantities and the requirement to include references to openly accessible price systems. Furthermore, errors relating to the specification of the quantity of works, units of measurement and descriptions of cost items were identified as having the largest impact on a project. Findings presented in this paper aim to highlight common errors in public tender documents and raise awareness of the need to improve their quality to ensure legislative compliance.