Abstract: Background: Fusarium stalk rot disease of maize is universally important because it is the most widespread destructive disease throughout the maize plantations all over the world including Southeast Asia. So far, the studies on the disease have not been carried out intensively in tropical countries including Indonesia, Malaysia and Thailand. Objective: The study was designed to determine the species and mating populations (MPs) of Fusarium in Gfsc associated with stalk rot disease in Indonesia, Malaysia and Thailand. Materials and Methods: A total of 106 strains of Fusarium in Gfsc were isolated from maize plants showing typical stalk rot symptoms and cultured on Potato Dextrose Agar (PDA) and carnation leaf pieces agar (CLA) for morphological identification. For MPs, the strains of Fusarium were crossed with 9 standard tester strains on Carrot Agar (CA). Results: Four species of Fusarium were morphologically identified as F. verticillioides (75%), F. proliferatum (20%), F. subglutinans (4%) and F. konzum (2%). Three mating populations were identified as MP-A, Gibberella moniliformis (71.7%), MP-D, G. intermedia (18.87%) and MP-E, G. subglutinans (2.83%) and 7 strains were not detected. All strains identified as MP-A, MP-D and MP-E were the strains morphologically identified as F. verticillioides, F. proliferatum and F. subglutinans, respectively. The MP-A (F. verticillioides) was the most dominant species associated with stalk rot disease of maize in this region. Conclusion: The results of biological identification and mating populations were corresponded to the results of morphological identification. This is the first report on the presence of MP-A, MP-D and MP-E on stalk rot-infected maize in Indonesia and Thailand, MP-A and MP-E in Malaysia. Additionally, the occurrence of F. konzum on stalk rot-infected maize plants are new records.