Influence of synthetic peptides identical to fragments of natural human immunodeficiency virus (HIV) glycoproteins gp 120 and gp 41, on luminol-enhanced chemiluminescence (CL) of human neutrophils has been studied. It was established that some of peptide analogs of gp 120 and gp 41 immunodominant regions are able to suppress spontaneous CL: but when being used with dimethylsulfoxide they dramatically stimulate it and deteriorate opsonized zymosan-induced CL. Conclusions about the necessity of possible side effects considering during use of peptide vaccines against HIV have been made. It is also possible to explain some neutrophil dysfunction in HIV infected subjects as the result of HIV glycoproteins direct influence on this cells.