The purpose of this study was to investigate the modulation of selected cell surface markers and proinflammatory cytokines production in relation to ageing, and cigarette smoking. The analysis of cell surface receptors was performed by the flow cytometry and cytokines levels were evaluated by the sandwich enzyme immunoassays. We found a decreased expression of CD69, CD28, CD11b, CD95 markers in old population compared to young people (p<0.05; p<0.001). The memory CD45RO lymphocytes were markedly expanded in older population in comparison to young donors (12.93+/-5.92 %, p<0.001) and the selectin CD62L was significantly increased on granulocytes in aged people (p<0.05). Our findings demonstrated an augmented level of CD3 and CD28 on lymphocytes in smokers (p<0.05; p<0.005). The significant depression of CD16+56 molecule was recorded in smokers (10.86+/-0.80%) when compared to non-smokers (14.44+/-0.46; p<0.05). Our results showed a significantly diminished levels of interleukin (IL)-1beta (1.93+/-0.48 pg/ml), and increased levels of IL-6 and tumor necrosis factor (TNF)-alpha in elderly population compared to young people (p<0.05; p<0.001). The present data support previous suggestions that senescence and cigarette smoking may contribute to changes in the immune system activity, resulting in altered cell surface marker expression and cytokine levels (Tab. 1, Fig. 3, Ref. 81). Full Text (Free, PDF) www.bmj.sk.