To compare the clinical outcomes of ≤6mm extra-short implants (test group) versus ≥10mm long implants (control group), with and without bone augmentation procedures. A systemic literature search of randomized clinical trials was performed using the PubMed (MEDLINE) and EMBASE databases. A quantitative meta-analysis was conducted to compare all the outcome variables. Meta-regression analysis determined the effect of bone augmentation procedures and the influence of other clinical covariates on the results. Eighteen studies comprising 1,612 implants (793 extra-short and 820 long implants) were selected for the meta-analysis. No statistically significant difference in the survival rate was observed at 1 and 3years (p>0.05). Extra-short implants displayed less marginal bone loss (MBL) from both implant placement time points (1 and 3years) and prosthetic placement (1year), as well as less biological complications, surgical time and treatment cost (p<0.05). Contrarily, a statistically significant small number of prosthetic complications were reported with long implants (p<0.05). Placement of extra-short implants (≤6mm) presented as an equivalent option in the treatment of patients with an atrophic posterior arch up to 3-year follow-up. However, the long-term effectiveness of extra-short dental implants remains to be further studied.