The present paper shows that a mixture of gangliosides (GA = GM1 + GD1a + GD1b + GT1b) is provided with a specific and powerful antinociceptive activity. The GA is active in reducing acetic acid and phenylquinone writhings, the acetic acid capillary-induced permeability and some acute inflammatory reactions. These actions seem to be mostly due to an anti-exudative property of the compounds which shows up right after the administration. The mixture of four gangliosides given in the proportion naturally occurring in the nervous system is more active than each single component in increasing the pain threshold, presenting therefore a synergistic effect. It is suggested that gangliosides can reduce the exudative phenomena interfering with the membrane permeability of the nerve-endings breaking interfering with the membrane permeability of the nerve-endings breaking the vicious circle of the neurogenic mechanisms of plasma extravasation.