Abstract: The invention relates to a device for interconnection of box-profile elements, comprising: an at least substantially rigid first connection element provided with multiple first receptors for parts of multiple box-profile elements, and at least substantially rigid second connection element adapted for cooperation with the first connection element, said second connection element being provided with multiple second receptors corresponding to the first receptors, for parts of multiple box-profile elements, and securing means coupled with the first connection element and the second connection element to secure the mutual connection of the first connection element and the second connection element. The invention also relates to the assembly of multiple box-profile elements and such a device. The invention further relates to a method for interconnection of box-profile elements.