A pneumatic tire comprises a sidewall reinforcing rubber disposed axially inside the carcass in each of the sidewall portion, and in order improving the ride comfort during normal running without deteriorating runflat performance, the axially inner surface of the sidewall reinforcing rubber is provided with a circumferentially extending groove. when the tire is deflated, the groove in the ground contacting patch is closed and the sidewall reinforcing rubber supports the tire load. when the tire is inflated-normally, as the sidewall portion can be bent around the groove, the ride comfort is improved.