A summary of the history of mammalogy in Paraguay is presented, from the work by Jesuit missionaries in the sixteenth century to the second decade of the twenty-first century. The last 40 years have seen a considerable increase in the number of individuals interested in the study of Paraguayan mammalogy, as well as in the number of published papers on the matter. As a result, the number of known species for the country has increased from 167 in 1998 to at least 183 in 2023. The inventory is far from complete, and an increase in species number is expected as knowledge is advanced. To date, except for a few emblematic species such as the jaguar (Panthera onca) or the Chacoan peccary (Catagonus wagneri), little is known on the ecology, evolution, or natural history of most Paraguayan mammals. Nonetheless, currently, Paraguay is in the process of creating the institutional framework to train the future Paraguayan researchers and wildlife managers. These efforts will encourage the development of mammalogy as a professional discipline in Paraguay and, in the long term, could translate into effective, countrywide conservation strategies.