In the present study, we investigated the mechanisms underlying the anti-inflammatory effects of rosmarinosin A in (LPS)-stimulated RAW 264.7 macrophages. The cells were pretreated with various concentrations of rosmarinosin A, and then stimulated with LPS. Rosmarinosin A reduced the production of nitric oxide (NO) and prostaglandin E2 (PGE2), possibly through the modulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, respectively. Additionally, it inhibited the production of pro-inflammatory cytokines, such as tumor necrosis factor α (TNF-α), interleukin (IL) 1β, and IL-6. The molecular mechanisms of rosmarinosin A involved the suppression of nuclear factor κB (NF-κB) p65 translocation into the nucleus. Furthermore, rosmarinosin A exhibited anti-inflammatory properties by suppressing the mitogen-activated protein kinase (MAPK) signaling pathway. These findings suggest that rosmarinosin A may exert its anti-inflammatory effects, at least in part, through the modulation of NF-κB and MAPK pathways in LPS-activated macrophages, offering the potential for therapeutic development.