Interferon (IFN)-gamma as a recombinant pharmaceutics, being launched in Iran as the third country in the world, despite its unclear genotoxic potential in in vivo models. In the present study, the genotoxic effects of this recombinant human IFNgamma were evaluated in peripheral blood lymphocytes from 24 healthy volunteers. The induction of chromosomal alterations including chromosomal aberrations, and micronuclei (MN) in binucleated cells were performed by different cytogenetic assays. Heparinized whole-blood samples from volunteers after cell pretreatment were treated with 0.33-66.6 IU/μl of IFN-gamma. The treated cells were then determined for chromosomal aberrations, and micronuclei in binucleated cells. The negative and positive controls were phosphate buffered saline (PBS), and mitomycin C, respectively. Results revealed that cells treated with IFN showed no significant difference from cells treated with PBS indicating this recombinant protein under the performed treatment regimen lacked of genotoxic potential.