The study was carried out with the purpose of knowing the parasitic indices of gastrointestinal helminths in rodents and wild marsupials of the Quebrada Blanco Biological Station, located on the right bank of the Quebrada Blanco, a tributary of the Tahuayo River, district of Fernando Lores, Loreto-Peru. . The rodents and marsupials were collected using 268 traps (120 Sherman, 120 hit and 28 Tomahawk) (Romero, 2017). The sample consisted of the digestive tracts of 25 rodents: 20 Proechimys sp., 3 Oecomys sp., 2 Scolomys sp. and 8 marsupials: 6 Marmosops sp. and 2 Monodelphis sp.; preserved in 10% formalin. The search for adult worms was carried out by direct observation of the gastrointestinal content through a stereoscope; internal organs were separated and rinsed with lactophenol for microscopic identification (Kennedy, 2016). Seven gastrointestinal helminths were identified: Spirura gu...