This article presents the tonal system of Laze, a.k.a. Muli Shuitian, a Sino-Tibetan language spoken in Sichuan. It is structured in terms of H(igh), M(id) and L(ow) levels, like in the closely related languages Naxi and Na. Tone sandhi plays a morphosyntactic role in Laze. There exist four lexical tones for Laze monosyllables: H, M, L and MH; in theory, this could yield as many as sixteen tone patterns over disyllables, but fewer are observed. The present research places special emphasis on (i) tonal changes in the combination of verbs with clitics: productive, synchronic sandhi rules, and (ii) tonal changes accompanying the lexicalization of compound nouns and of predicates made up of a noun plus a verb.