As matrix metalloproteinases (MMPs) play an important role in rheumatoid arthritis, we investigated whether variation in MMP genes was associated with functional disability in rheumatoid arthritis patients. A cohort of patients with seropositive rheumatoid arthritis were recruited and genotyped for the MMP1-1607 1G > 2G, MMP3-1612 5A > 6A, MMP7-153C > T, MMP7-181G > A, MMP12-82A > G and MMP13-77A > G polymorphisms. Genotypes were then analysed in relation to functional disability assessed by Steinbrocker index and Health Assessment Questionnaire (HAQ) score. We detected an association between the MMP13-77 A > G polymorphism and Steinbrocker index, with patients of the A/A genotype having higher score than patients of the A/G or G/G genotype (P = 0.005), and the association remained significant after adjusting for age, sex, erythrocyte sedimentation rate, presence of erosive disease, Ritchie score, prednisolone therapy and years of diagnosis (P = 0.003). We also observed a relationship of Steinbrocker index with the MMP3-1612 5A > 6A, MMP7-181 A > G and MMP12-82A > G polymorphisms (P = 0.082, P = 0.037 and P = 0.045). No association was detected between the MMP1-1607 1G > 2G and MMP7-153C > T polymorphisms and either Steinbrocker index or HAQ score. These results suggest that MMP3, MMP7, MMP12 and MMP13 genotypes may play a role in determining functional status of rheumatoid arthritis.