OBJECTIVE:: The objective of the study was to systematically review the medical literature reporting on potential clinical prognosticators for the outcome of external cephalic version (ECV). STUDY DESIGN:: Medline, EMBASE, and Cochrane Central Register of Controlled Trials were searched. Studies reporting on potential clinical prognosticators and ECV success rates that allowed construction of a 2 × 2 table were selected. RESULTS:: We detected 53 primary articles reporting on 10,149 women. Multiparity (P ≥ 1.00; odds ratio [OR], 2.5; 95% confidence interval [CI], 2.3-2.8), nonengagement of the breech (OR, 9.4; 95% CI, 6.3-14), a relaxed uterus (OR, 18; 95% CI, 12-29), a palpable fetal head (OR, 6.3; 95% CI, 4.3-9.2), and maternal weight less than 65 kg (OR, 1.8; 95% CI, 1.2-2.6) were predictors for successful external cephalic version. CONCLUSION:: Success of an ECV attempt is associated with clinical factors. This should be taken into account in the counseling of women prior to an ECV attempt.