130 patients, aged between 18 and 75 years, undergoing arthroscopic knee surgery were randomized to evaluate the efficacy of celecoxib as a pre-emptive analgesic 24 hours post-operatively. Pain intensity, opioid consumption, and side effects (nausea, vomiting, and dizziness) were assessed in both the placebo and the celecoxib group, as well as in the two subgroups of each treatment group of patients: the ACL reconstruction and meniscectomy subgroups. The results obtained in this study demonstrated that the use of celecoxib is effective in decreasing pain intensity and opioid consumption. No significant differences between groups for side effects were observed.