This research aims to describe the process of ecological succession by associating the decomposition stages of pig carcasses with flies from the Calliphoridae family (Diptera). For this, 6 pig carcasses were exposed in Maranhão's Cerrado, utilizing metal cages with sawdust trays to catch immature specimens and “suspended traps” to capture adults. Adults of the Hemilucilia benoisti Séguy, and Hemilucilia townsendi Shannon species were only associated with the swelling stage. Chrysomya megacephala (Fabricius) was associated with 2 stages (black putrefaction and fermentation). The species Chloroprocta idioidea (Robineau-Desvoidy), Chrysomya albiceps (Wiedemann), Cochliomyia macellaria (Fabricius), and Lucilia eximia (Wiedemann) were associated with 4 of the 5 stages of decomposition, the latter being the only 1 associated with the initial stage. The larvae abandoned the carcasses to pupate from the second stage of decomposition, with L. eximia being the only 1 leaving the carcasses in the swelling stage, and C. albiceps the only 1 associated with both the fermentation and dry stages. Our findings indicate that calliphorid species can help forensic investigators estimine the postmortem interval of cadavers in situations similar to those detailed in this study. Since there was a link between adult and immature species and certain stages, they can be used as indicators in future forensic investigations.