Studies on individual Amazonian languages have shown that these languages can contribute to informing and refining our theories of counterfactual conditional constructions. Still missing, however, is an attempt at exploring this complex sentence construction across different genetic units of the Amazonia in a single study. The paper explores counterfactual conditionals in a sample of 24 Amazonian languages. Special attention is paid to the range of TAM markers and clause-linking devices used in counterfactual conditionals in the Amazonian languages in the sample. As for TAM markers, it is shown that protases tend to be unmarked (they do not occur with any TAM values), and apodoses tend to occur with irrealis or frustrative marking. As for clause-linking devices, it is shown that most Amazonian languages in the sample contain counterfactual conditionals occurring with non-specialized clause-linking devices. This means that the distinction between counterfactual conditionals and other types of conditionals (e.g., real/generic) is not grammaticalized in clause-linking devices. Instead, the counterfactual conditional meaning resides in the combination of specific TAM markers. The paper also pays close attention to the distribution of TAM markers and clause-linking devices in counterfactual conditional constructions in the Vaupés. In particular, special attention is paid to how Tariana counterfactual conditional construction have been shaped by Tucanoan languages through language contact.