Large predators are the most well-known type of animals around the world, ranging from tigers, lions, bears and wolves who roam terrestrial ecosystems, to sea otters and nile crocodiles who maunder aquatic ecosystems. Despite their ubiquitous popularity, their populations are in imminent danger. Large carnivore and predator populations are experiencing a precipitous decline which can lead to a colossal imbalance in ecosystems. Over the past two centuries, predators have experienced geographic range contractions, fragmentation of habitat, and loss of individuals through hunting. This literature review analyzes and explains how the decline in large carnivore and predator populations can lead to indirect consequences within and across ecosystems. Using an ecosystem services valuation approach, this paper demonstrates how large predator conservation is not only economically justified, but imperative for widespread ecosystem stability.