||The genus Metrosideros (Myrtaceae) comprises 50-60 species, found largely across the Pacific Islands. The relationships within this genus, including the circumscriptions of the subgenera Mearnsia and Metrosideros and their relationships with the other members of the tribe Metrosidereae, namely the New Caledonian endemic genus Carpolepis and the South American Tepualia, are poorly understood. Phylogenetic analyses were carried out using previously published ITS sequences, covering most species of the tribe, and new sequences of five single-copy nuclear genes on a reduced sampling. The independent and combined analyses of the five nuclear genes using a range of approaches, including Bayesian single-gene, concatenated (MrBayes), concordance (BUCKy) and coalescent (*BEAST) analyses, yielded different topologies, indicating important conflicts among individual gene phylogenetic signals. The deep relationships within the tribe Metrosidereae remain poorly resolved, but our results indicate that the species of Carpolepis and Tepualia are likely nested in the genus Metrosideros. A broad circumscription of the genus Metrosideros is therefore adopted, and the new combinations Metrosideros laurifolia var. demonstrans, Metrosideros tardiflora and Metrosideros vitiensis are here published.