Taro (Colocasia esculenta [L.] Schott) is an important tropical crop cultivated throughout the world. In May 2017, symptoms of leaf blight were observed on approximately 40% of taro cultivar Lipu at a commercial field (5.33 ha) located in Zhanjiang (21.17N, 110.18E), China. Initial leaf symptoms were yellow to brown, striped to irregular-shaped, followed by necrosis spreading into interveinal areas. Ultimately, the affected leaves turned dark brown and became cracked and withered. To identify the pathogen, the symptomatic leaves were surface sterilized with 75% ethanol for 60 s and rinsed three times with sterile water before isolation. Potato dextrose agar (PDA) was used to culture the fungus. Successively, pure cultures were obtained by transferring hyphal tips to new PDA plates. Fifteen Alternaria isolates were obtained from 20 leaves (with an isolation frequency of 75%). Three single-spore isolates (Col-1, Col-2, and Col-3) were obtained and confirmed to be identical based on morphological characteristics. The isolates were grown on PDA and formed colonies of approximately 5 cm (diameter) in 5 days at 28°C. Colonies were gray-black in color, and conidiophores were branched and brown. Conidia were two to six in chains, dark brown, ovoid or ellipsoid, had one to four transverse and zero to three longitudinal septa, most beakless or with a short conical beak, and measured 6.5 to 32.5 (average 19.6) × 3.5 to 8.5 (average 6.2) μm (n = 30). Morphological characteristics of the isolates (Col-1, Col-2, and Col-3) were consistent with the description of Alternaria alternata (Fr.) Keissler (Simmons 2007). The internal transcribed spacer region, glyceraldehyde-3-phosphate dehydrogenase, and translation elongation factor were amplified using primers ITS1/ITS4, GDF1/GDR1 (Berbee et al. 1999), and EF-1α-F/EF-1α-R (O’Donnell and Cigelnik 1997), respectively. Amplicons were sequenced and submitted to GenBank (accession nos. MN460667 to MN460669, MN460670 to MN460672, and MN460673 to MN460675, respectively). The sequences of the three isolates were 100% identical to A. alternata (AF347031, KP124155, and KC584634) by BLAST analysis, respectively. Also, the sequences were concatenated for phylogenetic analysis by the neighbor-joining method. Therefore, the fungus associated with leaf blight of taro was identified as A. alternata. Pathogenicity tests were performed on cultivar Lipu with three leaves grown in pots (one plant per pot) using two methods. Mycelial plugs (Col-1) were applied to wounded leaves (with a sterilized pin) or control uninoculated agar plugs, with two plugs per leaflet across five replicate plants. A second method of inoculation was performed by applying spore suspensions to unwounded leaves. Sterilized cotton balls were immersed in a spore suspension (1 × 10⁶/ml) or sterile water for 1 min and then affixed to plants for 48 h, with two cotton balls per leaflet across five replicate plants. The test plants were maintained in a greenhouse with 80% relative humidity at 24 to 30°C for 12 days. After 7 days on wounded leaves and 12 days on unwounded leaves, yellow-brown spots were observed, and A. alternata was reisolated from each spot as described above. No symptoms were observed on control plants, and no A. alternata was isolated. A. alternata causes disease on various host plants (Woudenberg et al. 2015), including taro in Brazil (Mendes et al. 1998). To the best of our knowledge, this is the first report of A. alternata causing leaf blight of taro in China. This disease has substantial potential to adversely affect taro production in this region, and control strategies are important to develop.