The aim of this work is to determine the specifics of the content of the contract on the construction, repair or modification of the ship. The work is based on examples of provisions from the contract on construction, repair or modification and the provisions of the Maritime Code (PZ) are analyzed in the part related to the construction, repair and modification of the ship. The provisions from the Obligatory Relations Act (ZOO) are mentioned when it comes to some rights and obligations of the contractual parties from the contract on the construction, repair or modification of the ship. The provisions related to the Croatian Ship Register (HRB) are highlighted. Also, the paper defines the types of contracts for work on the ship and the essential elements of such contracts. The rights and obligations of the parties are analyzed, with special attention being paid to the issue of ownership of the ship under construction, mortgage on the ship under construction and guarantees. The international unification instruments related to contracts on the construction, repair and modification of ships are highlighted. Finally, the provisions related to the inspection of the ship, insurance and termination of the contract are highlighted. In the conclusion, all established specifics of the content of the contract on the construction, repair or modification of the hill are summarized. It is stated that there are three types of contracts for work on the ship, which are governed by the same regulations. Finally, in the conclusion, given all the established specifics of the contract on the construction, repair or modification of the ship, it is pointed out that it is a very complex contractual relationship that required a detailed analysis of the content due to its importance in the maritime industry.