Purpose – the article discusses the construction documents and their significance enshrined in Contractual Regulations and aims to disclose the consequences of the preparation or non-preparation of the construction documents for the client and the contractor. For this purpose, the general features of construction documents shall be reviewed first, and the certificate of acceptance of construction work and reports shall be analyzed separately.

Findings – the results of the study state that in client/contractor relationship, the rights and duties between the participants to a construction project and the preconditions for the cooperation between the parties in a legal relationship in construction are determined and provided in the construction documents. All construction documents that have been analyzed are drawn up specifically for construction work. On the one hand, the law gives the right or imposes an obligation on to the client and the contractor to sign and deliver the construction documents to another party in a legal relationship in construction. On the other hand, signing (non-signing), submission (non-submission) of the acceptance certificate of construction work and reports can lead to a division of responsibilities between the client and the contractor (who are often business entities), the obligation to eliminate the defects in the work, to compensate for the damage, and to pay for work.

Research limitations – though Lithuania has similarities with other EU countries in terms of the legal environment of construction, the generalisation of these results to another context is limited.

Practical implications – the findings could be directly applied in practice. Understanding and using the findings could prevent disputes between owners and contractors in practice.

Originality/Value – there is a lack of publications on the subject. Construction documents regulate the contractual relationship (performance of work, settlement, elimination of defects, etc.) between the client and the contractor. Therefore, proper and timely preparation of these documents is an important part of the implementation of contractual relationship both for business entities and the public using construction results.