Inflammation was induced in the guinea-pig palatal mucosa by a carrageenin solution injection. The inflammatory process was studied by a stereologic procedure. A determination was made of the volume fraction occupied by collagen, edema and vessels 1, 3, 6, 12, 24 hours and 4 days after the injection. The non-treated animals group presented a maximal collagen volumetric density decrease 6 hours after the carrageenin injection. The volume fraction of collagen then increased to reach approximately a value similar to the healthy mucosa collagen volumetric density 4 days after the injection. Edema was correlatively maximal 6 hours after the carrageenin injection and decreased during the next hours. During the whole course of the experiment, the volumetric density of vessels was higher than in healthy mucosa. The modification of the inflammatory process in the group of animals treated by the lipidic plants extracts (15 mg daily during 60 days before the carrageenin injection) mainly consisted in a stabilization of the vessels volumetric density during the experiment. The lipidic plants extracts would act as an inhibiting factor of the inflammatory vascular neoformation.