OBJECTIVES: The objective was to review all the reasons provided by the European Medicines Agency (EMA) to substantiate the need for revisions to or updates of disease-specific scientific guidelines developed by the Committee for Medicinal Products for Human Use (CHMP). METHODS: All the scientific guidelines issued by the CHMP were reviewed on the EMA’s website. The guidelines not focusing on disease-specific issues were not selected, i.e., guidelines listed in the following sections: Clinical Pharmacology and pharmacokinetics, General, Herbal Medicinal products, Information on medicinal products, and Radiopharmaceutical and diagnostic agents. RESULTS: A total of 182 disease-specific scientific guidelines were reviewed. The review identified 21 concept papers developed with the intent of revision (11.5% of specific guidelines). The analysis of the concept papers revealed that four main reasons were claimed: (1) Clarifications needed for pediatric development [10 concept papers: acute heart failure, asthma, Crohn’s disease, hepatitis C, hypertension, glucocorticoid-induced osteoporosis, irritable bowel syndrome (IBS), multiple sclerosis, pain, and ulcerative colitis); (2) Evolution in the field and treatments (n=9); (3) Clarifications on endpoints identification and measurement (n=7); and (4) Safety aspects (n=6). For instance, in asthma, one of the critical aspects to be discussed regarding endpoints was “the need to reinforce the use of clinical measurements (symptoms) and patient-reported outcome measures to complement lung-function parameters.” In IBS, regulators asked that “An evaluation whether more clear recommendations as regards the use of certain scales or newly developed PROs can be made is also desirable.” CONCLUSIONS: The main reason for the EMA to revise disease-specific guidelines is the need for providing guidance in pediatric issues. This is in line with the introduction of Pediatric Investigation Plans (PIPs) by the European Commission in January 2007 to help ensure that medicines for children are included in the mainstream drug development process in Europe.