Current guidelines recommend that percutaneous coronary intervention (PCI) should be restricted to the culprit vessel in ST elevation myocardial infarction (STEMI) patients with multi-vessel disease (MVD) and without cardiogenic shock. However, newer data suggests that performing complete revascularization (CR) in MVD patients may lead to better outcomes compared to intervention in the culprit vessel only. The aim of this meta-analysis is to examine the available data to determine if CR (using either angio- or fractional flow reserve guidance—FFR) following primary PCI in STEMI patients without cardiogenic shock impacts clinical outcomes. Meta-analysis was performed by conducting a literature search of PubMed from January 2004 to July 2017. Pooled estimates of outcomes, presented as odds ratios (OR) [95% confidence intervals], were generated using random-effect models. A total of 9 studies (3317 patients) were included. CR showed a significant MACE reduction (OR 0.49, 95% CI 0.36–0.66, p < 0.001); All-cause mortality (OR 0.69, 95% CI 0.48–0.98, p = 0.04) and repeat revascularization (OR 0.38, 95% CI 0.28–0.51, p < 0.001) at ≥ 12 months follow-up. The FFR-guiding CR group presented a MACE reduction (odds ratio 0.52, 95% CI 0.30–0.90, p = 0.02) due to a decrease of repeat revascularization (OR 0.41, 95% CI 0.21–0.80, p = 0.009). Overall, performing complete revascularization in STEMI patients showed a MACE reduction, all-cause death and repeat revascularization. Compared to culprit-only revascularization, treating multi-vessel disease in STEMI patients using FFR guidance is associated with decreased incidence of MACE, due to a decreased rate of revascularization.