This paper argues that a domain-based approach can be used to explain the complex tonal structure of Xhosa nouns by means of a single H tone spread rule. The argument proposes an H tone-motivated domain structure for every noun type, referred to as Tone Domains (TDs), with the number of TDs determined by the number of lexical H tones in a given word. It is then demonstrated that the H tone in each TD spreads to its right edge provided the Obligatory Contour Principle (OCP) is not violated. The significance of this approach is that it explains why the prefixal H tone would spread to the penult in some words and to the antepenult in others. It also explains why the preprefixal H tone is subjected to the rule in some nouns but not in others. (MDM).