It has been unexpectedly found that certain blends of styrene-butadiene rubber and platey filler exhibit both good gas barrier properties and good tensile fatigue properties. These blends accordingly have the requisite characteristics for a tire innerliner material. They offer the advantage of being much less expensive than halobutyl rubbers which can be employed for the same purpose. The present invention more specifically discloses a pneumatic tire having an integral innerliner wherein said innerliner is comprised of a blend of (1) from about 40 phr to about 99 phr of a first styrene-butadiene rubber having a bound styrene content of about 15 percent to about 30 percent, (2) from about 1 phr to about 60 phr of a high styrene content styrene-butadiene rubber having a bound styrene content of about 40 percent to about 60 percent, and (3) from about 40 phr to about 125 phr of platey filler. The subject invention also discloses a pneumatic tire having an integral innerliner wherein said innerliner is comprised of (1) a styrene-butadiene rubber having a bound styrene content of about 15 percent to about 30 percent, and (2) from about 125 phr to about 200 phr of platey filler.