HIS STUDY presents the Portulaca foliosa Ker Gawl. as a new species in the flora of Saudi Arabia. The plant was found scattered in limited locations in Alabna escarpment, southwestern Saudi Arabia, growing in a rocky, humid habitat between 1400-1800 m.a.s.l. Five species belonging to the genus Portulaca were reported in Saudi Arabia, namely P. oleracea L., P. quadrifida L., P. grandiflora Hook., P. kermesina N.E.BR., and P. pilosa L. These species have similarities in their shoot and floral structures. However, the obtuse leaves, retuse petals, and the flower's coluor are features that distinguish the new taxon from the other species. The newly recorded species is easily distinguishable from the other five Portulaca species through its small flower with bright yellow petals. To facilitate identification, distribution and habitat, detailed vegetative and floral descriptions, colour photographs, a map showing locality along with a new key for the genus Portulaca in the flora of Saudi Arabia are given.