Two new species of Thyronectria growing in Mediterranean vegetation are described from southern Spain; they are T. giennensis from Quercus ilex ssp. rotundifolia and T. pistaciae from Pistacia lentiscus. Both species are characterized by morphology of sexual and asexual morphs and by DNA data. They have olivaceous to green-brown muriform ascospores and are closely related to T. asturiensis and T. roseovirens, as determined by multigene phylogenetic analyses of a matrix containing six loci (ITS and 28S regions of nuc rDNA, ACT1, RPB1, RPB2, TEF1 and TUB2 genes). We also report that Cucurbitaria bicolor is a synonym of Thyronectria rhodochlora, the type species of Thyronectria.