Two cases with hyperinfection syndrome caused by Strongyloides stercoralis in the development of HIV/AIDS were reported. These patients had a severe immunodepression with lymphocyte counts of the subpopulation of CD4+ T cells under 200 cells/mm3. In the first case, a predominance of respiratory manifestations was observed and numerous Strongyloides rhabditiform larvae were found in sputum and faeces. In the second case, the neurological manifestations were more common, but only a larva of Strongyloides stercoralis could be detected per microscopic field (100X of magnification) in faeces. Both individuals in spite of the applied therapeutics had a fatal end. The importance of this paper is to be aware of the possibility of an infection disseminated by this helminth in some patients, and to be ready for a suitable diagnosis and an adequate treatment or prevention of the fatal consequences of the infection caused by this nematode.