A hybrid immobilisation device which is provided to cover at least a part of a patients' body that needs to be supported and/or immobilised, the immobilisation device being at least partly made of a plastic material. The immobilisation device comprises at least one first (1, 11) and at least one second part (2, 12) which are connected to each other in view of forming the immobilisation device, the first part (1) being provided to at least partly cover the body part to be immobilised and being made of a material comprising a first thermoplastic material having a first melting temperature T1, the second part (2) being made of a second material comprising a plastic material having a second melting temperature T2, T2≧T1 to allow for either a separate or simultaneous moulding of the first part (1) and second part (1, 2) after the first and second part have been assembled, the first part (1) being connected to the second part (2) in such a way that the first thermoplastic material and the second plastic material at least partly overlap.