Pathologic chronic inflammation, such as that seen with microbial infection and autoimmune diseases, creates microenvironmental conditions that promote cancer. Therefore, if chronic inflammation can be alleviated, the risk of carcinoge- nesis may decrease. Turmeric is a dried rhizome powder from Curcuma longa. Curcumin, the major constituent of turmeric, presents anti-inflammatory, antioxidant, antimicrobial and chemopreventive activities. In the present study, we investigated immune responses to dietary turmeric in ICR mice to determine the effects of turmeric when used as a dietary chemoprevention agent. After dietary turmeric was given for three or six weeks to ICR male mice, the immune responses were characterized. The methods of characterization involved; the determination of the T cell subpopulation in the spleen, relative mRNA expression levels of IFN-γ and TNF-α and serum lysozyme activity. Dietary turmeric was found to decrease spleen weight, decrease the proportion of CD4-CD8+ T cells, and decrease phagocytic activity. These results suggest that turmeric might alleviate abnormal chronic inflammation by the action of immune suppression.