OBJECTIVES: Patients with chronic pain due to osteoarthritis (OA) or rheumatoid arthritis (RA) do not often obtain adequate relief or experience unacceptable side effects due their pain-control treatments. The objective of this study was to perform a cost-effectiveness analysis comparing celecoxib, etoricoxib and lumiracoxib in the treatment of chronic pain in patients with OA and RA, from the Mexican Social Security Institute (IMSS) perspective. METHODS: A decision-tree model (12-weeks time horizon) was used to compare pain reduction and direct medical costs associated to competing alternatives. A systematic literature review was performed to identify the pain reduction (reported through visual analogue scales) and adverse events (AE) incidence rate associated. Comparators were: celecoxib 200mg/day, etoricoxib 90mg/day and lumiracoxib 100mg/day for patients with OA and RA. A meta-analysis with selected publications (n=10) was performed. Resource utilization was extracted from clinical practice guidelines and unit costs were retrieved from IMSS official sources. Probabilistic sensitivity analysis was performed. Acceptability curves were developed. RESULTS: Pain reductions vs. placebo were: celecoxib 14.18% (CI95% 10.48-17.87, p<0.00001); etoricoxib 12.70% (7.67-17.73, p<0.00001) and lumiracoxib 9.47% (7.17-11.77, p<0.00001). Differences between celecoxib and lumiracoxib was meaningful (p<0.05). The odds ratios of AE incidence vs. placebo were: 1.06 (0.77-1.46, p=0.37); 1.09 (0.87-1.36, p=0.73) and 1.44 (0.88-2.34, p=0.14), respectively. The expected medical costs (2011 US$) were: $197.93 (±$9.52); $221.54 (±$7.06) and $306.65 (±$12.86), respectively. The cost of management of AE contributed with $101.28, $95.00 and $146.17 of the overall expected costs, respectively. In regards to etoricoxib (basecase), celecoxib showed to be a cost-saving strategy with a cost-effective proportion of 76.7% (74.1%-79.3%); while lumiracoxib was the less effective and more costly strategy. CONCLUSIONS: At IMSS, celecoxib patients who suffer OA or RA would reach a higher incremental reduction in pain intensity at 12 weeks reducing overall costs in comparison to etoricoxib.