Objective: Zingiber cassumunar Roxb. has been reported to possess anti-inflammatory properties. However, little is known about its effect on macrophages. In this study, effects of Zingiber cassumunar and its derivatives on nitric oxide (NO) production, iNOS expression and NF-κB activation in LPS-stimulated macrophages were investigated. Material and Method: RAW264.7 macrophages were pretreated with ethanolic extracts and the constituents (DMPBD, compound B, compound B' and compound D) of Zingiber cassumunar at the concentration of 100 µg/ml for 4 h before stimulating with LPS (100 ng/ml) for 24 h. Then, NO levels in conditioned media were determined using Griess reagents. The mRNA levels of iNOS were detected by real time PCR. Effects of test substances on MAPK and NF-κB in LPS-stimulated- RAW264.7 were determined using western blotting. Results: Crude Zingiber cassumunar extracts, DMPBD, compound D, compound B, and compound B' at 100 µg/ml significantly inhibited NO release from LPS stimulated macrophages (p<0.05). iNOS expression and NF-κB activation were obviously inhibited in macrophages treated with LPS. Conclusion: Our findings suggest that Zingiber cassumunar extracts, DMPBD, compound B, compound B' and compound D could inhibit NO production in LPS-stimulated macrophages through the suppression of iNOS and NF-κB activation.