ObjectiveThe aim of this study was used meta-analysis to investigate changes of serum tumor necrosis factor-alpha (TNF-α) in patients with type 1 diabetes mellitus (T1DM).MethodsRelevant literatures were identified from PubMed, Cochrane Library, CNKI, WanFang and Chinese-Cqvip databases (published from January 1, 1999 to September 30, 2016). Eligible reports were included for pooled analysis of serum TNF-α level and subgroup analysis was performed in relation with age, disease duration and ethnicity.ResultsA total of 23 articles (1631 T1DM cases, 1429 healthy controls) were included for this meta-analysis. Compared with the controls, the patients had significantly increased serum TNF-α level (P < 0.001). Similar results were also found among all subgroup analysis of different age, disease duration and ethnicity (with the exception of Asian) (all P < 0.05). Regression analysis indicated that age (P = 0.680), disease duration (P = 0.957), and ethnicity (P = 0.526) of patients were not significant impact factors for the high heterogeneity. The results were stable according to the sensitivity analysis and no publication bias existed in this meta-analysis.ConclusionsSerum TNF-α level in T1DM patients has significantly elevated among all age, disease duration and ethnicity groups.