Stakeholders are debating the value of cognitively focused instruction for students who have not benefited from a skills-based approach. Much of the discussion, however, is occurring without recognition of research that has been conducted in the past 2 decades. In this article, we reviewed the research. Electronic databases and hard copies of scholarly journals were searched; 239 references were identified; and 50 pertinent studies were analyzed to determine the effects of cognitively focused instruction--delivered alone or in combination with academic instruction--on students described as demonstrating poor academic achievement, learning disabilities, or specific cognitive deficits. Findings suggest that several cognitive interventions accelerated low-achieving students' academic progress. Nevertheless, when the research is taken as a whole--when the pertinent studies and the interventions they describe are considered with regard to their content, quality, and results--we conclude that it does not support the use of cognitively focused instruction at this time. Implications for future research are discussed. (Contains 3 tables.)