OBJECTIVES: The PROQOLID database was developed in mid-2001 to provide all those involved in health care evaluation with a comprehensive and unique source of information on Patient-Reported Outcomes (PRO) and Health-Related Quality of Life (HRQL) measures available through the Internet. The objective of this study is to review the evolution of content, structure, and functionality of the PROQOLID database over this ten-year period (2002-2011). METHODS: The archives of PROQOLID were searched to retrieve the database just before its launch and to compare its content and structure as it is in December 2011. RESULTS: The September 2001 database (then known as QOLID) was retrieved. It included 313 instruments (32 generic and 281 disease- or condition-specific). Instruments specific to oncology were the most frequent (54). The structure was simple with only three categories in the membership level: contact, conditions of use, and a copy of the questionnaire. By comparison, the December 2011 database includes 711 instruments (an increase of 127%, with 99 generic and 612 disease- or condition-specific), with an increase of almost 40 instruments each year (up by 398 in ten years). Instruments specific to nervous system diseases are now the most frequent (139). The information displayed for each instrument has considerably been improved with the addition of five categories in the membership level: translations available, descriptive information, content validity documentation, measurement properties, references and websites. A search engine has been added to enable advanced searches with the following criteria: abbreviation, full name, author, dimension, disease, type of instrument, population, and languages. In January 2005 the database was renamed PROQOLID to reflect the wider use of the term Patient-Reported Outcomes. CONCLUSIONS: In a period of 10 years, the PROQOLID database has considerably evolved in content, and structure, and offers a range of information and services adapted to the evolution of the field.