Very similar to Band-rumped Storm-Petrel, and closely related to it. Both taxa differ mainly in timing of breeding and subsequent wing molt: Monteiro's Storm-Petrel breeds in summer and molt post-breeding, while Band-rumped breeds in winter and molts in winter. Morphologically they are very similar, however Monteiro's has on average a longer and more deeply-forked tail. Breeds in burrows and crevices on islands.