Background:Although dental implant therapy is considered a predictable treatment modality with reported high survival and success rates, biological complications do occur, and a number of risk factors have been involved. Tobacco smoking is related to many health risks affecting general & oral health. Objectives: The aim of this systematic review and meta-analysis is to test the null hypothesis of no difference in dental implant failure rates and marginal bone loss between smokers and non-smokers with regards to follow-up time. Search methods: An extensive electronic search was performed in PubMed, Scopus and EBSCOhost Dentistry and Oral Sciences source to identify relevant articles published up to June 2019. The eligibility criteria included randomized and non-randomized clinical trials & prospective & retrospective observational studies. After a thorough selection process, 23 papers were included. The meta-analysis was expressed in terms of the odds ratio (OR) or standardized mean difference (SMD) with a confidence interval (CI) of 95% and the level of statistical significance was set at P < 0.05. Results: There was a statistically significant difference in marginal bone loss favoring the non-smoking group with a SMD of 1.07 (95% CI 0.67–1.48), demonstrating a statistically significant difference in favor of non-smokers (P Author’s conclusion: Based on the results of this review, the null hypothesis is rejected, and that is in agreement with other reports in the literature. Therefore, the clinical recommendation for a period of abstinence from smoking that at least covers the pre-surgical evaluation & initial therapy, definite implant treatment & immediate post-op phases remains to be very relevant.