The descriptions (up to isomorphism) of naturally graded p-filiform Leibniz algebras and p-filiform (p ≤ 3) Leibniz algebras of maximum length are known. In this paper we study the gradation of maximum length for p-filiform Leibniz algebras. The present work aims at the classification of complex p-filiform (p ≥ 4) Leibniz algebras of maximum length.