Twenty-six species recently described from Thailand are revised. Eleven taxa are reduced to synonymy with previously described species, including Leptotrema phaeosporum var. vainiona Räsänen. The following new combinations are proposed: Chapsa calathiformis (Vain.) Lumbsch & Papong, C. laemensis (Homchantara & Coppins) Lumbsch & Papong, Melanotrema melanophthalmum (Homchantara & Coppins) Lumbsch & Papong, Ocellularia albocincta (Hale) Divakar & Mangold, O. guianensis (Sipman) Divakar & Mangold, O. khunantensis (Homchantara & Coppins) Lumbsch & Papong, O. percolumellata (Sipman) Divakar & Mangold, O. subcalvescens (Nyl.) Divakar & Mangold and Ocellularia subgranulosa (Homchantara & Coppins) Lumbsch & Papong.