Cumulated evidence indicates that matrix metalloproteinase-3 (MMP-3) is significantly involved in cancer progression. Recent studies yielded conflicting results regarding the association between serum MMP-3 and ankylosing spondylitis (AS). To clarify this correlation, we performed a meta-analysis. Potential relevant studies were identified by searching the following databases: PubMed, Embase, CINAHL, Science Citation Index database, the Cochrane Library, Current Contents Index, Chinese Biomedical, the Chinese Journal Full-Text, and the Weipu Journal. Data from eligible studies were extracted and included into the meta-analysis using a random-effect model. Standardized mean differences (SMDs) and 95% confidence intervals (CIs) were used to assess the association between serum MMP-3 levels and AS. Thirteen case-control studies, including 707 AS cases and 442 healthy controls, were selected for the meta-analysis. The results indicate a significantly higher serum MMP-3 level in patients with AS than that in the controls (cases vs controls: SMD = 1.31, 95%CI = 0.84-1.78, P < 0.001). Ethnicity-subgroup analysis indicated a higher MMP-3 level in Asian and Caucasian patients with AS (all P < 0.05). This meta-analysis indicates that increased serum MMP-3 level correlates with the development of AS, suggesting that MMP-3 may present a clinical value in reflecting the progression of AS. Further larger sample size studies are warranted.