The aim of this study was to determine whether the functional chemokine receptor 5 delta32 (CCR5-Delta 32) polymorphism confers susceptibility to rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA). Meta-analysis was conducted on associations between the CCR5-Delta 32 polymorphism and RA and JIA using (1) allele contrast and (2) the recessive, (3) the dominant, and (4) the additive models. Eleven population comparisons based on the data obtained from nine studies involving 13,412 subjects (RA 3,848, controls 4,095; JIA 1,599, controls 3,870) were considered. In all study subjects, meta-analysis showed a significant negative association between RA and the CCR5-Delta 32 allele (OR = 0.771, 95 % CI = 0.694-0.866, p = 6.5 x 10(-7)). Stratification by ethnicity indicated a significant association between the CCR5-Delta 32 allele and RA in Europeans (OR = 0.8001, 95 % CI = 0.709-0.904, p = 3.2 x 10(-5)). Meta-analysis showed associations between the CCR5-Delta 32 allele and JIA in Europeans and oligoarticular type (OR = 0.797, 95 % CI = 0.690-0.921, p = 0.002; OR = 0.475, 95 % CI = 0.352-0.693, p = 9.5 x 10(-8)). This meta-analysis demonstrates that the CCR5-Delta 32 polymorphism may confer susceptibility to RA and JIA in Europeans, and suggests that the CCR5-Delta 32 allele protects against the development of RA and JIA.