Parmotrema is a large genus in the Parmeliaceae family with approximately 350 species of foliose lichens, which are mainly distributed in the tropical areas. Parmotrema tinctorum (Despr. ex Nyl.) Hale is one of the most popular species in this genus wildly growing in Vietnam. Previous studies found that the extracts of P. tinctorum exhibited significant antioxidant [1], antibacterial [2], and antifungal activities [3]. The chemical investigation of this lichen revealed the presence of atranorin, lecanoric acid [4, 5], atranol, methyl haematommate, divaricatinic acid, methyl divaricatinate [5], methyl β-orsellinate, orcinol, gyrophoric acid, lecanorin, lichenxathone [6], isolecanoric acid [7], salazinic acid [8], orsellinic acid, and methyl orsellinate [9]. In this study, we report on the chemical constituents of P. tinctorum species and their antifungal activity collected in the highland region of Vietnam. Fourteen natural compounds (1–14) were isolated and their chemical structure determined. Among those, there are four compounds firstly identified from P. tinctorum lichen. Furthermore, four orsellinic acid derivatives (3, 4, 9, 10) showed antifungal activity against Colletotrichum sp., Fusarium oxysporum, and Pyricularia oryzae strains.