A tire for a vehicle wheel includes a carcass structure, a belt structure, a tread, a pair of sidewalls, and at least one layer of sealing composition placed in a radially inner position with respect to the tread. The carcass structure includes at least one carcass ply shaped in a substantially toroidal configuration. Opposite lateral edges of the carcass structure are associated with respective bead wires. The belt structure includes at least one belt strip. The sealing composition includes at least one high molecular weight amorphous polymer, at least one low molecular weight amorphous polymer, and at least one reinforcing filler. The sealing composition is substantially non-crosslinked and has a flowability value, measured at a temperature of 100.degree. C. and at a pressure of 30 bar, not higher than 30 cm.sup.3/s. A process for producing the tire for a vehicle wheel is also disclosed.