From May to October of 2006 we collected 143 louse flies of the genus Lipoptena on the body surface of 16 pampas deer Ozotocerus bezoarticus captured in four farms from the central area of the Brazilian Pantanal wetlands. We also examined 172 cattle individuals and none of them had louse flies. Most of the parasites identified were Lipoptena guimaraesi but one specimen of L. mazamae was also found, representing a new host record for this ked fly. The prevalence of L. guimaraesi was 93.8%, the mean intensity of infestation was 9.5, and the index of discrepancy was 0.444.