Nojirimycin (NJ) is a compound in which the oxygen of the ring is replaced with an NH group in the D-glucose structure. NJ, which has a structure similar to D-glucose, is a powerful glucosidase inhibitor and an interesting compound. However, no anti-inflammatory effects of NJ have been reported. Therefore, to investigate its anti-inflammatory effect, the production and expression of inflammatory cytokines, as well as inflammatory mediators, such as iNOS and COX-2, were measured in LPS-stimulated RAW264.7 macrophages. In addition, the effects on the representative inflammatory signaling pathways, the suppression of NF-κ B, and the activation of MAPK were studied. The production of iNOS, COX-2, and inflammatory cytokines (PGE₂, IL-6, IL-1β, and TNF-α) after NJ treatment was significantly inhibited. In addition, NJ showed anti-inflammatory effects through suppression of LPS-induced NF-κ B activation. D-Glucose is structurally similar to NJ. The effects of these substances on RAW264.7 macrophages were evaluated. NJ reduced nitric oxide (NO) levels, whereas D-glucose had no significant effect. Overall, the results suggested that NJ is a potential anti-inflammatory compound.