Freshwater fish survey was conducted in Tikub Lake, a landlocked crater lake with an area of 48.34 hectares nestled at the foot of Mt. Malepunyo which is shared and bordered by Barangay Ayusan I and Barangay San Pedro in Tiaong, Quezon, Philippines. A total of 221 individuals comprising 9 species from 7 families were found in Tikub Lake, three of which are native and six are introduced. Diversity index was 1.87. A native, Giuris margaritacea and an introduced, Poecilia sphenops are the two most abundant species in the lake with relative abundance of 29.41% and 26.24% respectively. Although the study revealed that Tikub Lake hosts diverse community of fish, this is due to different introduced species as the lake is being utilized for aquaculture. Other uses of the lake include subsistence fishery, and to limited extent recreation and tourism. Just like any other lake ecosystems of the country, Tikub Lake experiences pressures due to different human activities both in the aquatic and terrestrial realms such as cutting of trees as wood fuel, excessive extraction of resources, and the ever increasing human population as evidenced by the presence of informal settlers. A sound community-based management strategy is a prerequisite to achieving environmental sustainability.