We studied the effect of aminosugars on the elastase enzyme released from cytochalasin-B treated polymorphonuclear neutrophils (PMN) and stimulated by F-Met-Leu-Phe (FMLP). Both N-acetyl-galactosamine and N-acetyl-glucosamine can inhibit the release of leukocyte elastase enzyme. N-acetyl-galactosamine was a potent inhibitor of elastase enzyme release in a dose-related fashion. Inhibition ranged from 91.9% up to total inhibition. N-acetyl-glucosamine showed a mild inhibitory effect on elastase enzyme release; however, it too acted in a dose-related fashion. The range of inhibition was 17.17%-8.18%. Mannosamine showed an inhibitory effect in some donors, but this effect was not statistically significant. No effect on elastase enzyme release was shown with other sugars such as D-glucose and L-fucose. These results show that N-acetyl-galactosamine can inhibit the respiratory burst, which suggests that the aminosugars might do more than interfere with the carbohydrate lectin interaction.