Lagusia micracanthus or locally known as pirik fish and is the only endemic freshwater fish from the family Terapontidae. To date, published information related to biological aspects of this species in the Gilireng River, Arajang Village, Wajo Regency, is unavailable. This study aims to determine the length--weight relationship and condition factors of L. micracanthus fish populations in the Gilireng River. Fish sampling was performed once a month January 2022 to June 2022. The fish collected from Gilireng River comprised 69 male and 66 females during the study period. Pirik (L. micracanthus) in the Gilireng River demonstrated nearly an isometric growth pattern. Condition factor values ranged from 0.6455 to 4.3239, and the average condition factor values for female fish were smaller than male fish. The result of this study has contributed to the knowledge of the endemic pirik fish population in the Gilireng River that could assist fishery management scientists in conducting studies on the management of these fish.