An open-label study was undertaken at multiple centers in Mexico to assess the impact of treatment with etoricoxib - a selective cyclo-oxygenase-2 (COX-2) inhibitor - on quality of life (QoL) and pain relief among patients with osteoarthritis (OA), rheumatoid arthritis (RA) or chronic low-back pain (CLBP). The study involved 191 adult patients (aged > 18 years old) who had used non-selective non-steroidal antiinflammatory drugs (NSAIDs) for the treatment of OA, RA or CLBP during the month prior to study enrolment. After discontinuation of prior therapy, patients were treated with etoricoxib 60 mg for OA and CLBP,or 90 mg for RA once daily for 2 weeks. Patient and physician questionnaires were used to collect information about drug treatments, patients' QoL (Short Form-8 Health Survey [SF8] and EQ-5D VAS), patients' pain assessment, and physicians' and patients' satisfaction with treatment at baseline and at follow-up visits. Relative to prior NSAID use, etoricoxib use was associated with improvements in all SF-8 QoL domains and component scores as well as in measures of pain and physical functioning. Current pain was reduced from 59.1 mm (0-100mm VAS) at baseline to 27.1mm at follow-up and the physical component score of the SF-8 improved from 33.3 to 46.3 (on a scale from 0 to100). At follow-up, 91% of patients were satisfied with the pain control provided by etoricoxib compared with 34% who were satisfied with the pain control provided by previous NSAIDs. Among physicians, 93% reported satisfaction with the analgesic effect, 95% with the anti-inflammatory profile, and 82% with the side-effect profile of etoricoxib relative to pre-study NSAID treatment. During etoricoxib therapy, use of concomitant medications was reduced. The results of this study are limited due to the lack of a control group, the un-blinded design, and the small number of patients. Large naturalistic trials are needed to confirm the results.