Western Naxi (纳语, 纳西语) has three tones (High, Mid and Low) plus a more recent rising contour tone. The first part of the article describes the synchronic process whereby the reduction of a morpheme carrying a High tone results in re-association of its tone to the preceding syllable, creating a rising contour. The second part presents the lexical items that carry a rising tone: ‘native' words carrying a rising contour tone point to the use of High-tone addition in possessive constructions at an earlier stage. The numerous Chinese loanwords with rising tone are probably not the origin of the rising tone of Naxi; they arguably led to the consolidation of a pre-existing rising-tone category.