A pneumatic tyre comprising a carcass (6) comprising a ply (9) of cords (10) defining the innermost reinforcing cord layer extending between bead portions (4), and an airtight layer disposed inside the cords (10) of the carcass ply along the inner surface of the tyre, covering the substantially entire inner surface of the tyre, wherein the airtight layer is made of air-impermeable rubber including at least 10 weight % of halogenated butyl rubber and/or halogenated isobutylene-paramethyl styrene copolymer in its rubber base, and a thickness (T2) of the airtight layer measured from the inner surface of the tyre to the cords of the carcass ply is in a range of from 0.2 to 0.7 mm. <IMAGE>
