Objectives: This study aimed to determine the number needed to treat (NNT) of ketorolac in comparison to placebo after third molar surgery. Methods: Studies located in PubMed, Scopus, and Web of Science were evaluated with the Cochrane Risk of Bias assessment tool. Data on the onset of analgesia, the number of patients requiring rescue medication, the global or general evaluation of the study medication, and adverse effects were extracted. Data analysis was performed using Review Manager 5.3 software for Windows. Results: The qualitative assessment of the included studies showed that ketorolac was more effective than a placebo and the quantitative evaluation on the onset of analgesia (NNT = 1.6 (95%CIs = 1.4, 1.9), n = 301), the number of patients who took rescue analgesics (NNT = 3.6 (95%CIs = 2.8 to 4.9), n = 563), and the global evaluation of the treatments (NNT = 1.7 (95%CIs = 1.5 to 1.9), n = 475) showed estimates of analgesic efficacy with a statistical difference in favor of ketorolac when compared with a placebo. No statistical difference was observed in adverse effects between ketorolac and placebo (n = 739). Conclusions: There is scientific evidence of moderate quality that allows estimators of the analgesic efficacy of ketorolac to be calculated, which will significantly help the clinician who performs pharmacological treatment after third molar surgery.