The estimate of the richness is an essential element in the characterization of biodiversity, so that regional inventories of certain groups of taxa as epigean coleopterans are important for planning conservation efforts in protected natural areas. By using accumulation curves and non-parametric estimators, the quality of various samples on estimating the richness of epigean coleopterans of the Pingüino Humboldt National Reserve (Atacama and Coquimbo Regions, Chile) was evaluated. The asymptotic models tested showed theoretical species richness close to that observed in the Choros and Damas islands, however in Chañaral Island no clear asymptote was observed, suggesting an incomplete inventory. All estimators evaluated showed richness values greater to the observed values for all the studied islands, however its accumulation curves did not stabilize in any island except for ICE and Jack 2 in Choros and Damas. We propose to conduct additional sampling in particular habitats of this reserve, as well as to include other seasons of the year and different years in order to register rare species not recorded to date by our sampling.