The article proposes an analysis of the most important document in the commercial transport of goods by sea i.e. the bill of lading. The multiple functions performed by this document are represented as follows: the bill of lading is a receipt for the goods delivered, it is the clear evidence regarding the terms covered by the contract of carriage and it is a document of title. By means of its functions, one obtains the analysis of the relationships between shipper/charterercarrier- consignee and in some cases, endorsee, types of bill of lading and their probative value, the relationship between charter contract and the bill of lading and finally, the conditions to be met so that the bill should be considered a document of title.