Polyethyleneimine (PEI) is a chemical compound that used is as a carrier in gene therapy/delivery. Some studies have investigated the microbicidal potential and antiviral activity (prophylactic or therapeutic) of PEI and its derivatives. The aim of this study was to investigate the effect of branched polyethyleneimine (bPEI) on human immunodeficiency virus (HIV) replication. Infected cells were treated with bPEI for 36 hours, and the concentration of the viral protein P24 (as a virus replication marker) was determined in cell culture supernatants. This study indicated that bPEI increased HIV replication and decreased the viability of infected cells through cytotoxicity. The toxicity of bPEI its association with and cell death (apoptosis, autophagy and necrosis) have been reported in several studies. To investigate bPEI-induced cytotoxicity, we examined apoptosis and autophagy in cells treated with bPEI, and a significant increase in HIV viral load, the P24 antigen level, autophagy, and necrosis observed. Thus, treatment with bPEI leads to cytotoxicity and higher HIV virus yield.