Recently it was demonstrated that phycocyanin, a biliprotein isolated from microalgae Spirulina, exerts anti-inflammatory activity in several animal models of inflammation. In this report, the effects of phycocyamin on prostaglandin E2 (PGE2) concentrations and phospholipase A2 (PLA2) activity were determined in arachidonic acid (AA) and 12-O-tetradecanoyl phorbol 13-acetate (TPA)-induced mouse ear oedema, respectively. Phycocyanin (50-200 mg/kg p.o.) inhibited in a dose-dependent manner PGE2 levels in mouse ear treated with AA. Also, phycocyanin (100-400 mg/kg p.o.) moderately reduced PLA2 activity in TPA-induced mouse ear inflammation test. In this model triamcinolone (10 mg/kg p.o.) used as reference drug exerted a remarkable inhibitory effect on PLA2 activity. These results provide the first evidence that the anti-inflammatory effects of phycocyanin may result, at least partially, from inhibition of PGE2 production and a moderate inhibition of PLA2 activity.