Despite advances in primary species records, quality and accessibility biases in information make it difficult to study spatial patterns of biodiversity. The first systematic analysis on the biases in the temporal and spatial distribution of records of continental land wild mammals from Colombia is presented. Through the use of databases, we identify administrative areas and ecoregions with the largest information gaps at the order level for the number of registered species with respect to the number of expected species. In addition, we carry out complementarity analyzes to establish priority sampling areas that help reduce biases in the registration patterns of mammalian species in Colombia. Most of the orders (70%) present a representation of less than 50% in at least 40% of the departments and 60% of the ecoregions studied. In addition, we found that the temporal coverage in cells of 50 * 50 km is low, with an average of less than four years from 1950 to 2019. The complementarity analysis shows that the registry of species at the national level would be maximized in the tropical forests of the Amazon in the limits between the department of Caquetá and Amazonas, the Guiana shield in the Orinoquia region, in addition to the savannah ecosystems of Vichada, Casanare and Arauca. We propose the definition of prioritization schemes and systematic sampling both for isolated and little-known areas, as well as for areas of greater anthropic pressure that may suffer local losses of species in the short term.