Our studies, and review of earlier records by others, have revealed the presence in Colombia of trypanosome infections in triatomine bugs as follows (“b”—trypanosomes identified biologically by developmental and transmission studies; “m”—identified by morphological criteria only): both Trypanosoma cruzi (b) and T. rangeli (b) in Rhodnius prolixus and Triatoma dimidiata capitata; T. cruzi (m) and T. rangeli (m) in Eratyrus mucronatus and R. pallescens; T. cruzi (m) in Cavernicola pilosa, Panstrongylus geniculatus, R. pictipes, Triatoma d. dimidiata, and T. venosa; T. rangeli (b) in R. brethesi; T. rangeli (m) in R. robustus. No infections were found in Triatoma maculata, and there are no records of infection in Belminus rugulosus, Eratyrus cuspidatus, Microtriatoma mansosotoi or Panstrongylus rufotuberculatus. Eratyrus mucronatus, Microtriatoma mansosotoi, Rhodnius brethesi and Triatoma maculata are recorded for the first time in Colombia, while the observation of T. rangeli (b) in the salivary glands of Rhodnius brethesi and T. rangeli (m) in Eratyrus mucronatus and R. robustus are new records for this parasite in any of these triatomine species. Domiciliary Rhodnius prolixus, the most important vector of human trypanosomiasis in Colombia, was also found in palm trees—an observation previously recorded in Venezuela, but the question whether these were in fact R. prolixus or the closely related and similar R. brethesi requires further assessment. One of the bugs found in a palm tree transmitted T. rangeli to a monkey experimentally, suggesting that arboreal triatomines may be vectors of at least some primate trypanosomes in the New World and perhaps also in the Old World. Assessment of all available records of the distribution of trypanosomes in bugs, man and animals in Colombia indicates that the Catatumbo, Oriental, and Magdalena River Valley natural regions are the most important endemic areas of trypanosomiasis. The Atlantic Coast region may prove to be as important for human trypanosomiasis as it seems to be for animal infections. The remaining regions—Pacific Coast, Central Massif and Cauca River Valley—seem to be less important, although a few human infections have been recorded and bats have been found infected. Since R. prolixus has been found at a wide range of altitudes (20 to 2600 m) and in sites which vary greatly in ecological characteristics, human trypanosomiasis may prove to be more widespread in Colombia than is presently recognized.