Abstract: OBJECTIVES: The aim of present study was the estimation of the anti-inflammatory effects of the somatostatin analog-octreotide in the adjuvant arthritis in rats. MATERIAL AND METHODS: The arthritis was induced by intradermal injection of Freund’s adjuvant at the foot’s pulvinar of the posterior paw in August’s strain rats. The animals received: 0.9% NaCl, octreotide (oct), dexamethasone (dx) and oct together with dx. The clinical signs, body weight, weight of spleens and thymuses were estimated. The cellularity of the thymus was evaluated by computer assisted morphometry and levels of IL-1 beta in serum were measured by the ELISA method. RESULTS: In the rats treated with oct in comparison to the untreated group the reduction of the clinical signs, a decrease of the body weight fall, inhibition of the thymus weight fall, the lower spleen’s weight, an increase of the thymus cellularity and an increase of the IL-1 beta level in serum were found. The rats treated with dx showed greater to oct-treatment reduction of the clinical signs and greater loss of the thymus weight. The spleen’s weight was similar to the healthy group. A significant reduction of the thymus cellularity and a decrease of the IL-1 beta level were also found. The rats treated with dx and oct jointly showed in comparison with dx alone a weaker reduction of the clinical signs, lower thymus weight fall, an increase of the IL-1 beta level in serum, without the significant influence on the other parameters. CONCLUSION: The octreotide shows the anti-inflammatory effect in adjuvant arthritis, but it is weaker in comparison to dexamethasone. Treatment with dx and oct together does not result in the more pronounced anti-inflammatory action of glucocorticoid alone.