The Individuals with Disabilities Act (Individuals with Disabilities Education Improvement Act; IDEIA, 2004) has been reauthorized, and new parameters for defining learning disabilities (LD) have been established that provide more flexibility for corresponding state and local regulations. The field now has a unique opportunity to shape the practice of LD diagnosis and should consider important conceptual, theoretical, empirical, economic, legal, and practical issues related to LD diagnosis. This article highlights five key recommendations for the diagnostic definition of learning disabilities: (1) the definition needs to be unambiguous; (2) it must be universally accepted across professions, researchers, and governmental entities; (3) it must incorporate clearly defined subtypes of learning disabiI ities; (4) it must be empirical ly supported; and (5) it must point to valid, reliable, and cost-effective procedures for the identification of children with and without learning disabilities. Consideration of these points may help the field to avoid repeating past mistakes and returning to the folly of poor LD diagnostic practice.