The presence of HLA-DRB1*0101 and HLA-DRB1*04 alelles were determined in a sample of fifty panamanian patients with severe arthritis reumatoidea and thirty five not affected individuals used as a controls. The HLA-typing was performed by polymerase chain reaction specific sequence primer (PCR-SSP). The alleles with shared epitope SE (+) were significantly higher among patients with RA, 68 % (p< 0.005) than in control group (34%). The relative risk (R.R.) associated to these alleles were estimated to 6.00. The most frequently ocurring SE (+) allele in RA patients was HLA-DRB1*0101 with a frequency of 38% compared to 17% of the control group. HLA-DRB1*04 alleles did not show any association with severe RA in panamanian patients. The only allele that show association with severe RA was HLA-DRB1*0101, p< 0.05 and R.R. =2.96.