Parque Bicentenario in the Área Natural Protegida El Espino-Bosque Los Pericos, considered the “last green lung of San Salvador”, is the most important forested area in central El Salvador. We performed a survey to provide the first inventory of scarab beetles (Scarabaeidae) of the park. Collections were conducted monthly for one year (August 2018–July 2019) by using baited pitfall, aerial, and ultraviolet light traps. Four subfamilies, nine tribes, 14 genera, 20 species (8% of the total richness of the family in El Salvador), and 1,584 individuals were captured. The most abundantly collected species in the park were the scarabaeines Onthophagus batesi Howden and Cartwright, Onthophagus belorhinus (Bates), Dichotomius centralis (Harold), Coprophanaeus corythus (Harold), Dichotomius yucatanus (Bates), and Coprophanaeus boucardi (Nevinson).