Imperatorin (IMT) is a furanocoumarin from the root of Phlomis younghusbandii (Lamiaceae) with various activities. In the present study, the anti‑inflammatory effects of IMT were evaluated by examining dimethylbenzene‑induced ear edema, acetic acid‑induced vascular permeability and by performing cotton pellet granuloma assessments in mice. In addition, the expression of pro‑inflammatory cytokines, including tumor necrosis factor (TNF)‑α, interleukin (IL)‑6 and IL‑1β, were detected using enzyme‑linked immunosorbent assay kits in mice and using reverse transcription polymerase chain reaction analysis in RAW 264.7 cells. The expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase‑2 (COX‑2), nuclear p65, cytosolic p65 and inhibitor of nuclear factor (NF)‑κB (IκB) in RAW 264.7 cells were determined using western blot analysis. The results showed that the oral administration of IMT significantly inhibited the inflammatory reactions and reduced the release of TNF‑α, IL‑6 and IL‑1β reactions and reduced and suppressed the mRNA expression of TNF‑A expressionact1o, and the protein expression of iNOS and COX‑2 in the RAW 264.7 cells. The results also indicated that IMT suppressed the activity of NF‑κB via upregulating p65 and IκB in the cytoplasm and downregulating p65 in the nucleus. In conclusion, IMT possessed notable anti‑inflammatory activities in vitro and in vivo through inhibiting the NF‑κB pathway.