In recent years, there has been an increasing number of studies on carrion fly communities due to their medical importance and as a consequence of the large number of studies on forensic entomology. Surprisingly few studies have adressed with the asynantropic flies of the Amazon, and none were done in Colombia. A faunistic study of asynantropic flies of the families Calliphoridae, Sarcophagidae, Muscidae and Fannidae in three different landscapes of the Colombian Amazon is presented, trapping effectiveness is assessed, and the first record of Mesembrinella batesi (Aldrich, 1922) and Fannia femoralis (Stein, 1897) from Colombia is reported. The decomposing activity of bacteria, fungi and carrion animal feedings is the main process by which nutrients are released and recycled from dead animals. Arthropods and mainly carrion feeding insects represent the most conspicuous element in this process (Nuorteva, 1977;Hanski, 1987). The role of necrophagous flies is ecologically important given their predominance, these community assemblages are very complex and highly competitive, usually dominated by one to three species (Hanski, 1987;Ives, 1991).In recent years, studies on carrion flies have increase. However, these studies have focused on synantropic environments and dealt mainly with faunal succession, lifecycles and species growth rates (Richards, 2001). Few known studies have been made from asynantropic conservation areas of the Amazonian rain forest e.g., Paraluppi (1992); Esposito, (1999) on blow flies (Diptera: Calliphoridae). Knowledge of necrophagous flies in the Colombian Amazon is sparse and consists mainly of isolated records of a few species: Guimaraes (1977) reported six species of Mesembrinellinae, Baumgartner & Greenberg (1984) reported the blowfly Chrysomya putoria in Leticia for the first time in Colombia; and recently Pape et al (2005) reported Hemilucilia segmentaria, Chloroprocta idioidea and seventeen species of flesh flies (Diptera:Sarcophagidae). Finally, Fannia obscurinervis (Diptera: Fannidae) hasbeen reported in the Colombian Amazon by Carvalho et al (2003) and Couri & Winagraski (2005).The study was carried out at the Biological Station "El Zafire" National University of Colombia (Leticia branch) located at 04°00'18'' S, y 69°54'45''W, altitude 146 m.Three different environments within the Amazon rain forest were surveyed: a firm land forest (L), a flood plain forest (F) and a white sand forest (W). In each site, three traps made from plastic PET bottles (Figure 1, further details in Ferreira, 1978) were set up 2 m above ground along a transect of 1500 m. Traps were baited with a one day old fish head in decomposition and specimens were collected every 12 hours during a period of 48 hours. Species accumulation curves and non-parametric estimators of total species richness ICE and Chao2 generated by StimateS 7.5 (Colwell, 2005) to assess the sampling efficiency and representatition of the sampling. Kruskall-Wallis test were used for difference in abundance and richness among hab...