The Reason for Encounter Classification (RFEC) was designed by a WHO Working Party to classify the reasons why patients seek care at the primary care level. It is designed along two axes: Chapters and Components. Each chapter carries an alpha-code which is the first character of the basic 3-character alphanumeric code. Each chapter is subdivided into seven "components" carrying 2-digit numeric codes. The field trial was undertaken by family physicians and nurses in: Australia, Barbados, Brazil, Hungary, Malaysia, the Netherlands, Norway and the US. 90497 RFE's were analysed. Their distribution over the chapters and components characterize the content of international primary care. Listings with the most common RFE's in the participating countries reflect the cultural differences. It is concluded that the RFEC is not only feasible to classify reasons why patients seek care but also to classify the diagnosis and the process of primary care. As a result of this, the International Classification of Primary Care (ICPC) succeeds the RFEC.