Objectives: To perform a methodical review of the evidence available for the efficacy of cognitive rehabilitation in individuals with diagnosed medical conditions known to affect cognitive function, and to establish evidence-based recommendations for clinical practice, as appropriate. Data Sources: Ovid Medline and PubMed literature searches were conducted using the terms cognition, cognitive, crossed with the terms rehabilitation, remediation, retraining, training, crossed with 11 medical diagnostic categories. Articles through December 2008 were accessed, with a resulting 2284 abstracts. Study Selection: A total of 211 articles were selected from initial abstract review. These articles were then assessed by committee members, with agreement of at least 2 members, using 9 exclusion and 3 inclusion criteria. A total of 34 remaining articles were submitted to full review. Data Extraction: Articles were reviewed under diagnostic categories using specific criteria recorded on structured data sheets. Classification was performed according to guidelines of the American Academy of Neurology, with agreement between 2 committee members necessary for final decisions. Data Synthesis: Of the 34 studies fully evaluated, 1 was rated as class I, 6 as class II, 2 as class III, and 25 as class IV. Evidence within each diagnostic area was synthesized for the formulation of Practice Standards, Practice Guidelines, and Practice Options, as possible. Conclusions: Two clinical practice recommendations were advanced, 1 each in the diagnostic areas of brain neoplasms and epilepsy/seizure disorders. Discussion included comments on the research status of the effectiveness of cognitive rehabilitation for cognitive deficits related to these medical conditions, as well as suggestions for future directions in research.