A lichenicolous fungus, Abrothallus henryanae, is described as new to science, which inhabits the apothecia of Sticta henryana. The lichen was collected from Arunachal Pradesh, India. The novel taxon is readily distinguished in having black, stipitate ascomata, covered by greenish-yellow pruina and two-septate, brown, finely ornamented ascospores. The novelty of the species is also confirmed through phylogenetic analyses of the internal transcribed spacer of the ribosomal DNA (nrITS) region. This is the first molecular study of lichenicolous fungi from India. A key to all known lichenicolous Abrothallus species colonizing Sticta in the world is also provided. Keyword: Abrothallus granulatae, Himalayas, mycobiota, molecular systematics, Northeast India, nrITS, phylogeny.