The Philippines has approximately 1,100 species of lycophytes and ferns, and this represents approximately 9% of the worldwide fern flora. Botanical explorations and local documentations continue to expand the list. Local documentations increase our knowledge on species distribution and conservation status, which are essential in biodiversity conservation. This paper reports on a survey of the pteridophytes of Adams, Ilocos Norte, one of the remaining floristic sites in Luzon Island, Philippines. A series of floristic surveys conducted at selected sites in Adams recorded and vouchered 47 species, 34 genera and 21 families of pteridophytes. Among all these pteridophytes, six are threatened Philippine plant species. These are Platycerium coronarium, Ceratopteris thalictroides, Tectaria psomiocarpa, Psilotum nudum, Blechnum egregium, and Angiopteris evecta. This study contributes to the baseline data on Philippine pteridophytes especially on their distribution, and can serve as reference for biodiversity conservation and restoration efforts as ferns may help in the stabilization of degraded lands and facilitation in plant communities.