In Hawai‘i and other oceanic islands with few native land mammals, black rats (Rattus rattus) are among the most damaging invasive vertebrate species to native forest bird populations and habitats, due to their arboreal behavior and generalist foraging habitats and habitat use. This is a selected data set used to assess the impacts of rodenticide treatment on black rat (Rattus rattus) abundance within Hawaii Volcanoes National Park (HAVO). The key objective was to identify rat abundance before and after rodenticide treatment, using paired non-treatment and treatment plots at high elevation (1700-1830m) and low elevation (1220-1340 m). This dataset includes the results of a mark recapture study that took place within a centralized 300x300 m (9 ha) portion of each 700x700 m (49 ha) study plot (two treatment and two non-treatment plots). Live trapping was conducted in a series of nine 4-day trapping periods from 2015-2017. Traps were placed 50 m apart in a grid fashion, with a total of 49 traps per plot. Rodenticide application commenced in the treatment plot in January 2017, in between the fall 2016 and spring 2017 trapping periods. The treatment covered the entire 49 ha plot at Kipuka Ki and Lower Keamoku, using bait stations containing 0.45 kg 0.005% diphacinone spaced 50 m apart (225 stations). Rats were reduced to low numbers throughout the treatment period, which continued from January through August 2017.