Predation events known as saurophagy occurs when lizards are involved as prey. Whether by cannibalism or saurophagy such events has been well documented in the last years. This paper report a predation event on Iguana iguana by Boa constrictor recorded in a fluvial island in the Amazonas River, Brazil. Also, provides a list of saurophagy events involving B. constrictor as predator. During a field trip we found an individual of B. constrictor in the process of ingesting a common green iguana (I. iguana), swallowing the headfirst on an upland forest. We found a total of eight lizards as prey of B. constrictor, belonging to three families: Iguanidae, Teiidae and Tropiduridae.