Decades of research have demonstrated that deaf children generally lag behind hearing peers in terms of academic achievement, and that lags in some areas may never be overcome fully. Hundreds of research and intervention studies have been aimed at improving the situation, but they have resulted in only limited progress. This paper examines cognitive functioning among deaf learners, describing and integrating research that indicates them to differ significantly from hearing learners in ways likely to affect learning. Findings demonstrating that deaf and hearing children differ in domains such as visual-spatial processing, memory, and executive functioning provide directions for both future research and practice. First, however, teachers and other professionals need to recognize that deaf children are not simply hearing children who cannot hear. Only then can teaching methods and materials fully accommodate their strengths and needs. (Contains 1 footnote.)