The anti-inflammatory and antinociceptive activities of cordymin, a peptide purified from the medicinal mushroom Cordyceps sinensis, were studied. The effects of cordymin on cytokine levels and total antioxidant activity were analysed. The antinociceptive effects of cordymin in vivo and in vitro were also determined. Cordymin treatment decreased the levels of tumour necrosis factor alpha, interleukin 1 beta and total antioxidant status. Cordymin inhibited the acetic acid-induced abdominal constrictions in mice in a dose-dependent manner. In the hot-plate test, results showed that cordymin significantly inhibited the reaction time to thermal stimuli at 30, 60 and 90 min. In neurolysin inhibition assay, cordymin showed strong activities against neurolysin (IC(50) = 0.1 µM). Our results show that cordymin is a potent anti-inflammatory and analgesic medicine.