The genus Decarloa (Naucoridae: Laccocorinae) is monotypic and endemic to the island of Hispaniola. Other than its inclusion in a catalog of the Naucoridae, nothing concerning it has been published since the original description. Recently, adults and second through fifth instars of Decarloa darlingtoni La Rivers were collected from Armando Bermudez National Park in the Dominican Republic. All specimens were collected from submerged rocks near the margin of a stream. Females have forelegs with a one-segmented tarsus and paired, articulated pretarsal claws; a pronounced lobe at the middle of the posterior margin of laterosternite V; and a subgenital plate with paired longitudinal carinae near the apex. The nymphal instars can be distinguished from one another based on overall size and relative length of the mesonotal wing pad compared with the exposed part of the metanotal lateral margin.