Kinyarwanda is a Bantu language spoken in Rwanda which exhibits puzzling alternation of the past-participal morpheme, which in certain contexts triggers sibilant harmony. Sibilant harmony is part of the broader class of consonant harmony, which has presented challenges to phonological theories. This presentation will present a sketch of Kinyarwanda phonology along with an analysis of sibilant harmony exhibited in Kinyarwanda under an autosegmental framework using mutation morphology. Finally, dialectical variation in sibilant harmony will be considered, comparing the Conogolese dialect with the Kigali dialect.