A four month survey was undertaken to document the diversity and abundance of reptiles in the Kukulugala forest (KF) in the Ratnapura District, Sri Lanka. A total of 708 individuals belonging to 41 genera (~50%) and 13 families (~55%) were recorded. KF had high species diversity with 58 species, representing about ~28% of the total diversity of known reptiles of Sri Lanka. Of the recorded species, 11 (~19%) were threatened and 24 (~44%) are endemic to Sri Lanka. Endemic relict genera including Aspidura, Balanophis, Cercaspis, Lyriocephalus, Ceratophora, Lankascincus and Nessia were also recorded during the survey. Availability of varied microhabitats may be responsible for the observed high species diversity. Anthropogenic activities, particularly illegal logging and man-made forest fires, is threatening these habitats leading to reduction in reptile population and diversity.