The synthesis of a new class of 9-(S)-dihydroerythromycin derivatives and their anti-inflammatory activity on in vivo PMA assay are described. Modifying the desosamine sugar on the C-3' amino group, it was possible to differentiate between anti-biotic and anti-inflammatory action. The compounds are completely devoid of anti-microbial effects but their anti-inflammatory properties are enhanced. These results strongly suggest the potential of macrolides as a new class of anti-inflammatory agents.