Abstract: A pipe (4) is rehabilitated by means of a tubular liner (5) which is introduced into the pipe in a contracted form, expanded into contact with the pipe wall, and hardened to retain its form. The liner (5) comprises composite material formed by knitting, braiding or weaving tows of intermingled filaments of thermoplastic and reinforcing fiber, the liner being heated during application to the pipe in order to melt the thermoplastic. The composite material may be created as a sleeve. Alternatively, a sheet of the material may be calendered and rolled up into a tubular form, overlapping edge margins of the sheet being bonded together after expansion of the tube into contact with the pipe wall.