Method for preassembling reinforcements for reinforced concrete consisting of a plurality of transverse stirrups suitable to be fixed to longitudinal bars in order to shape a reinforcement cage, the method characterised by the steps of: a. prearranging an interception plane associated with a centering device for a stirrup b. prearranging a mobile support plane for said stirrups, mobile in a direction perpendicular to said interception plane and cooperating with said centering device associated with said interception plane c. prearranging a device for feeding at least one flexible and inextensible interconnection element d. feeding a said first stirrup to said interception plane, centering it on said plane by means of said centering device e. uniting said interconnection element to said first stirrup by means of a uniting device f. performing the controlled feed of a predetermined extension tract of said interconnection element by means of said feeding device g. in suitable step relationship with said step f. of performing the controlled feed of said interconnection element, releasing said first stirrup united to said interconnection element towards said mobile support plane h. repeating steps from b. to g. in order to unite further stirrups to said interconnection element i. performing in suitable step relationship the operation of said mobile support plane in a direction perpendicular to said interception plane, receiving by said operation said stirrups united to said interconnection element in condition of compacted preassembly, wherein said stirrups united to said interconnection element are approached to each other between said interception plane and said mobile support plane and said interconnection element is folded in bights towards the inside of said stirrups. a. prearranging an interception plane associated with a centering device for a stirrup b. prearranging a mobile support plane for said stirrups, mobile in a direction perpendicular to said interception plane and cooperating with said centering device associated with said interception plane c. prearranging a device for feeding at least one flexible and inextensible interconnection element d. feeding a said first stirrup to said interception plane, centering it on said plane by means of said centering device e. uniting said interconnection element to said first stirrup by means of a uniting device f. performing the controlled feed of a predetermined extension tract of said interconnection element by means of said feeding device g. in suitable step relationship with said step f. of performing the controlled feed of said interconnection element, releasing said first stirrup united to said interconnection element towards said mobile support plane h. repeating steps from b. to g. in order to unite further stirrups to said interconnection element i. performing in suitable step relationship the operation of said mobile support plane in a direction perpendicular to said interception plane, receiving by said operation said stirrups united to said interconnection element in condition of compacted preassembly, wherein said stirrups united to said interconnection element are approached to each other between said interception plane and said mobile support plane and said interconnection element is folded in bights towards the inside of said stirrups.