Tumor necrosis factor antagonists are useful in the treatment of several chronic inflammatory immune mediated diseases. Aim: To assess the effects of infliximab in 21 patients with inflammatory arthropaties, refractary to conventional treatment. Patients and methods: Eleven patients with rheumatoid arthritis, seven with psoriatic arthritis and three with spondyloarthritis were treated. The mean duration of the diseases was 10 years. Infliximab was administered intravenously in a dose of 3 mg/kg body weight. A median of 6 doses in 8 months was administered. Effectiveness was assessed in 19 patients that received three or more doses. Results: Infliximab was effective in 16 patients (10 with rheumatoid arthritis, four with psoriasis and two with spondyloarthritis) and ineffective in three. In responsive patients, a reduction in the number of inflammed joints and morning stiffness and an improvement in functional capacity was observed. Fifteen of the 16 patients perceived an improvement in their health status. This answer was concordant with concomitant medical evaluation in 15. Patients that maintained the treatment felt very well, well or regular, whereas five of six patients that discontinued the treatment felt ill. Thirteen patients had adverse effects. Treatment was discontinued in two patients due to drug induced lupus, allergy in 2, hypertension in one, high costs in three and lack of response in three. Conclusions: Infliximab reduced arthritic activity in 16 of 19 patients with severe treatment refractary arthritis (Rev Méd Chile 2003; 131: 1157-64).