In the present study, in order to investigate the anti-proliferative phenomenon of PLME, the effects of mycelial extract of Phellinus linteus (PLME) on the growth of human lung carcinoma cell line A549 was examined. We studied on the effects of PLME on the release of nitric oxide (NO) in mouse macrophage Raw 264.7 cells. Treatment of PLME to A549 cells resulted in the growth inhibition, morphological change and induction of apoptotic cell death in a dose-dependent manner as measured by MTT assay. We found that PLME stimulated a dose-dependent increase in NO production. These findings suggest that PLME enhances the anti-tumoral activity of macrophage and may be a potential therapeutic agent for the control of human lung carcinoma cells.