Previous studies with intraarticular administration of somatostatin (SST14) in rheumatoid arthritis showed an antiinflammatory and analgesic effect. The aim of the present study was to demonstrate the efficacy and tolerability of SST14 in rheumatoid arthritis (RA) patients for a longer period of treatment than previously scheduled. Forty-one patients with RA of the knee were treated with a cycle of intraarticular injection of 750 micrograms of SST14, every 15 days. The efficacy of SST14 was evaluated by determining acute phase parameters (erythrocyte sedimentation rate, C-reactive protein [CRP]) and by clinical assessment (pain at rest and on movement, joint tenderness, morning stiffness, spontaneous pain). Additionally, telethermography was performed to evaluate the intensity of the joint inflammation. The tolerability of the treatment was also assessed both by patients and physicians. SST14 produced a reduction in all parameters; this was already statistically significant after the second injection in terms of pain at rest and on movement, and after the third injection for all other symptoms. The treatment showed an excellent tolerability, both local and systemic. Our results indicate the analgesic property of SST14 and demonstrate its capacity to reduce progressively joint inflammation confirmed by thermography and by reduction of pain, after a month of therapy.