 They are also extremely opportunistic and can be seen scavenging on fatty tissue of dead marine mammals and also trailing behind fishing boats.Fork-tailed storm petrels have a well-developed olfactory system and heavily rely on odour to scout for food, so often they are the first birds to arrive at a pungent food source.When at the source, these birds seize their prey by fluttering across the water surface and may occasionally dive to depths of 0.6 m.

Like other Procellariiformes, the fork-tailed storm petrel produces stomach oil from its digested food and stores it in its proventriculus, a section of the bird's digestive system.