To provide a polyester tire cap ply cord which has high elastic modulus and remarkably improved fatigue resistance and adhesiveness to rubbers, and to provide a method for producing the same.

This method for producing the polyester tire cap ply cord includes treating a polyester fiber material in a first treating bath containing (A) a polyepoxide compound, (B) a blocked polyisocyanate compound and (C) a rubber latex and having a solid content weight ratio (A)/[(A)+(B)] of 0.05 to 0.9 and solid content weight ratio (C)/[(A)+(B)] of 0.5 to 15 as a treating liquid to impart adhesiveness to rubbers to the polyester fiber material, treating the polyester fiber material in the second treating bath containing a resorcinol-formalin-rubber latex, and then thermally treating the treated polyester fiber material under a normalizing tension adjusted to ≥0.2 cN/dtex.