This study examines whether or not MBD4 polymorphism is a marker for rheumatoid arthritis (RA) susceptibility or severity for Chinese patients in Taiwan. This study included 193 patients with RA, while 190 unrelated healthy individuals living in Central Taiwan served as controls. The relationship between MBD4 polymorphism and clinical manifestations of RA was evaluated. For the genotype and allelic frequency of MBD4-1057 polymorphism, there were no statistically significant differences between patients with RA and controls. There were significant differences in the distribution of MBD4-8666 polymorphism frequencies between patients with RA and controls [P = 0.013; P (corrected) (Pc) = 0.039]. There were also significant relationships in the distribution of MBD4-9229 polymorphism genotype between patients with RA and controls (P = 0.007; Pc = 0.021). However, we did not detect any associations for MBD4-1057, MBD4-8666 or MBD4-9229 with rheumatoid factor presence, extra-articular involvement or bone erosion in patients with RA. Results suggest that MBD4-8666 and MBD4-9229, but not MBD4-1057, gene polymorphisms are related to RA in Chinese patients in Taiwan.