A novel disease of mango (Mangifera indica L.) was observed in the main mango growing regions (Minab, Bandar Abbas and Roudan) of Hormozgan province, southern Iran. Disease symptoms included leaf and fruit blights as well as twigs and branches dieback. The disease incidence in the field conditions ranged from 15.3% to 27.3%. A black yeast-like fungus was consistently isolated from symptomatic tissues and identified as Aureobasidium melanogenum using cultural and morphological features as well as partial nucleotide sequence data derived from two gene loci, including internal transcribed spacer region (ITS1–5.8S-ITS2) and D1/D2 domains of the large subunit (26S) (LSU-rRNA) of the ribosomal DNA gene. BLASTn searches of the ITS and LSU sequences in the NCBI GenBank revealed 99–100% nucleotide similarity to several A. melanogenum strains. A phylogeny inferred using sequence data from ITS and LSU sequences placed our isolates together with the other A. melanogenum in the GenBank. Koch's postulates were fulfilled by inoculating stems, leaves and fruits with A. melanogenum isolates. To our knowledge, this is the first report worldwide of A. melanogenum on mango.