Background: The risk of infectious, autoimmune and immunodeficiency diseases and cancers rise in opioid addicts due to changes in innate and acquired immune responses. Three types of opioid receptors (К،δ،μ) are expressed on the surface of lymphocytes and mononuclear phagocytes. The present study was designed to examine the effects of different concentrations of opium on the secretion of some cytokines produced by lymphocyte cells. Methods: Jurkat cells were exposed to different concentrations of opium for periods of 6, 24 and 72 h in cell culture medium. The amount of interleukin-6 (IL-6), interferon-γ (IFN-γ) and transforming growth factor-b (TGF-β) were then measured using enzyme-linked immunosorbent assay (ELISA) method. Findings: The results showed that opium increases the secretion of IL-6 in different concentration of opium in 6 h. The amount of IFN-γ decreased in 6 h and increased in 24 h significantly compared with control. On the other hand, opium had an inhibitory effect on the TGF-β secretion in 6, 24 and 72 h. Conclusion: Overall, the study showed that opium stimulates pro-inflammatory and suppressed anti-inflammatory cytokine secretion in Jurkat cells. This may account for the negative effect of opium on the immune system leading to chronic inflammation and a base for many disorders in opium addicts.