The invention relates to a method for producing a tubular hollow body (1) with at least three pipe openings, partly or completely consisting of plastics material. It is provided that a lost core pipe (9), which has a connection opening (13, 14) on each of its ends and has at least one docking opening (11) along its length, is produced, that the core pipe (9) is introduced into a cavity of a mould, with two non-lost core pieces (17, 18) being arranged with one of their ends (3, 4) respectively against the connection openings (13, 14) in a sealing manner and a non-lost core part (19) being arranged with one end against the docking opening (11) in a sealing manner, in that plastics material (25) is then introduced into the mould cavity to encapsulate the core pipe (9), the core pieces (17, 18) and the core part (19) and that, once the plastics material (25) has cured, the core pieces (17, 18) and the core part (19) are withdrawn from the hollow body (1) created. The invention also relates to a corresponding hollow body (1).