In this manuscript, we demonstrate metamaterials based on two-dimensional high density arrays of metallic multiwalled carbon nanotubes. They demonstrate a cutoff response toward electromagnetic waves and can be utilized for filtering applications. The plasma frequency, where the metamaterial displayed a sharp change in the reflection and transmission, depends on the geometry of their two-dimensional cubic lattice. A plasma frequency in the near infrared region of 1.5 μm was calculated numerically, for an array consisting of multiwalled nanotubes, having radius of 50 nm and lattice constant of 400 nm. Reflection experiments conducted on the nanoscale structures were in excellent agreement with numerical calculations.