Purpose: To evaluate the survival rate of mini implants used to retain mandibular overdentures. Materials and Methods: An electronic search, supplemented by hand searching of the references, was conducted with no time or language restriction in October 2016 and updated in October 2017. The results were reviewed independently by the two authors. All randomized controlled trials, clinical trials, observational studies, and case series were included. The primary outcome measure was implant survival (months). Results: The search retrieved a combined total of 391 articles. Following screening, 17 articles were included. A total of 1,715 mini implants were assessed in 475 patients. Follow-up periods ranged from 6 to 84 months (mean: 28.24 months). There were 75 failures in total. The overall survival rate was 95.63%. The majority of patients received four implants to retain their prostheses. Most studies used a flapless surgical technique, but there were vast differences in loading protocols and retention methods. Formal meta-analysis was not conducted due to the heterogeneity between studies. Conclusion: Based on the findings of this systematic review, mini dental implants exhibit excellent survival rates in the short to medium term. They appear to be a reasonable alternative treatment modality to retain mandibular complete overdentures from the available evidence. Keywords: complete dentures, failure, mini implants, survival, systematic review