Post-operative pain exacts a high toll from patients, families, healthcare professionals and healthcare systems worldwide. PAIN-OUT is a research project funded by the European Union's 7th Framework Program designed to develop effective, evidence-based approaches to improve pain management after surgery, including creating a registry for feedback, benchmarking and decision support. In preparation for PAIN-OUT, we conducted a pilot study to evaluate the feasibility of international data collection with feedback to participating sites. Adult orthopaedic or general surgery patients consented to participate between May and October 2008 at 14 collaborating hospitals in 13 countries. Project staff collected patient-reported outcomes and process data from 688 patients and entered the data into an online database. Project staff in 10 institutions met the enrolment criteria of collecting data from at least 50 patients. The completeness and quality of the data, as assessed by rate of missing data, were acceptable; only 2% of process data and 0.06% of patient-reported outcome data were missing. Participating institutions received access to select items as Web-based feedback comparing their outcomes to those of the other sites, presented anonymously. We achieved proof of concept because staff and patients in all 14 sites cooperated well despite marked differences in cultures, nationalities and languages, and a central database management team was able to provide valuable feedback to all.