Lichen biota of Pathanamthitta district of Kerala state was thoroughly studied which resulted in 24 lichen species as new to Kerala and one species, Phaeographis nylanderi (Vain.) Zahlbr. as new to India. All the species identified are either crustose or foliose forms belonging to families Graphidaceae and Caliciaceae indicating the dominance of these groups in the study area. List of all the 25 species are provided along with their distribution. Keywords: Biodiversity, Caliciaceae, Endemic, Graphidaceae, Lichenized fungi, Western Ghats.