This article provides evidence that the mora, rather than the syllable, is the tone-bearing unit in Kabiye, an Eastern Gurunsi Gur language of Togo. After presenting the phoneme inventory and a brief overview of the tone system, the concept of phonological weight is introduced in order to precisely characterise the mora and the syllable in this language, as well as the relationship between them. Two observations provide evidence in favour of the mora as the tone-bearing unit: first, contour tones are licenced on heavy syllables but not on light ones; second, tonal processes are sensitive to a unit smaller than the syllable, such that the second constituent of a heavy syllable operates with a degree of independence relative to the first. These observations are explored in four phonological domains: association of the LHL tone pattern, association of two-tone patterns, L tone spreading, and vocalic elision. Two post-lexical processes — contour realignment and HLH plateauing — provide putative evidence of the syllable as tone-bearing unit, but even in these cases, a moraic account is ultimately judged to be preferable.