The three language families indigenous to the Caucasus exhibit a range of diverse, unusual, and highly complex agreement phenomena. Nakh-Daghestanian languages are dominated by ergative-aligned gender agreement in which the absolutive argument controls agreement on the verb, and potentially other clausal elements like adverbs or even pronouns. Special agreement patterns like long-distance and biabsolutive agreement emerge in certain syntactic configurations. Northwest Caucasian is polysynthetic; its verbs register features from each of their arguments in a distinct templatic slot. These languages also have special agreement for arguments that undergo A̅-extraction. Kartvelian agreement is not straightforwardly linked to syntactic roles, and morphemes exhibit many complex blocking relationships. Dative-subject constructions “invert” the normal morpheme–role mappings, adding another dimension of complexity to the languages’ agreement systems. This chapter describes typologically and theoretically notable agreement phenomena found in these three language families, highlighting micro- and macro-variation, drawing parallels to other language families, and citing relevant theoretical and experimental studies. For reference, the chapter concludes with an appendix of agreement paradigms.