The aim of this work was to combine the properties of chlorobutyl rubber (CIIR) and natural rubber (NR) in a binary blend for application in the inner liner of tubeless tires, using organomodified montmorillonite (Cloisite^® 15A) as filler in order to improve the barrier property of the material. The maintenance of the mechanical and barrier properties of CIIR/NR 60/40 indicated that this blend can be used in the inner liner of tubeless tires, thereby reducing the cost of the final product, since the CIIR is 80% more expensive than NR.