[4] The species appears to have been introduced in Florida, although it is unknown whether the small population (thought to derive from escaped pets) is reproductive.

Observations and analysis of gut and waste contents from regularly flooded areas in the Pantanal region of southwestern Brazil indicate that they are generalist feeders that employ both ambush predation and wide-foraging strategies.

Their prey consists nearly exclusively of aquatic or semi-aquatic species, including a wide variety of mammals, birds, reptiles, amphibians, fish and eggs.

Juveniles and the occasional adult may be taken by caimans, larger anacondas, jaguars, cougars, some canids such as the crab-eating fox, mustelids, and raptors.

[10] In captivity, the yellow anaconda has a reputation for being unpredictable and somewhat dangerous to humans, especially when caught from the wild, leading some professionals and keepers to begin efforts at captive-breeding.